METHODS FOR PREPARING PEROVSKITE SOLAR CELLS (PSCS) AND THE RESULTING PSCS
20250008752 ยท 2025-01-02
Assignee
- University Of Louisville Research Foundation, Inc. (Louisville, KY)
- Alliance For Sustainable Energy, Llc (Golden, CO)
Inventors
- Thad Druffel (Louisville, KY)
- Craig A. Grapperhaus (Jeffersonville, IN)
- Sashil CHAPAGAIN (Louisville, KY, US)
- Peter James ARMSTRONG (Louisville, KY, US)
- Blake Martin (Louisville, KY)
- Marinus Franciscus Antonius Maria van Hest (Golden, CO, US)
Cpc classification
C01G53/40
CHEMISTRY; METALLURGY
H10K30/40
ELECTRICITY
C01P2002/72
CHEMISTRY; METALLURGY
C01P2002/88
CHEMISTRY; METALLURGY
International classification
H10K30/40
ELECTRICITY
Abstract
Some embodiments of the invention include inventive methods for preparing perovskite solar cells (PSCs). In certain embodiments, the method comprises dissolving a functionalized material (e.g., a material that is functionalized with one or more functionalizing compounds) in a solvent, depositing a deposit composition on a perovskite layer where the deposit composition comprises the dissolved functionalized material, heating the deposit composition, and optionally removing some or all of the one or more functionalizing compounds from the deposit composition. Additional embodiments of the invention are also disclosed herein.
Claims
1. A method for preparing a Perovskite Solar Cell (PSC), the method comprising: dissolving a functionalized material in a solvent, where the functionalized material is a material that is functionalized with one or more functionalizing compounds; depositing a deposit composition on a perovskite layer, where the deposit composition comprises the dissolved functionalized material; heating the deposit composition; and optionally removing some or all of the one or more functionalizing compounds from the deposit composition.
2. The method of claim 1, wherein the material of the functionalized material comprises one or more of an organic material, a metal oxide, TiO.sub.2, SnO.sub.2, NiO.sub.x, CuO, ZnO, Zn.sub.2SO.sub.4, WO.sub.3, In.sub.2O.sub.3, SrTiO.sub.3, Nb.sub.2O.sub.5, BaSnO.sub.3, C.sub.60, C.sub.70, PC.sub.61BM, PC.sub.71BM, or fullerene.
3. The method of claim 1 or claim 2, wherein the material comprises one or more of a doping substance.
4. The method of any of the preceding claims, wherein the material comprises one or more doping substances and the one or more doping substances comprises Zr, Sb, Li, Mg, Y, Nb, Cu, or Mo.
5. The method of any of the preceding claims, wherein the material of the functionalized material comprises one or more of an organic material, a metal oxide, a doped metal oxide, TiO.sub.2, SnO.sub.2, NiO.sub.x, CuO, ZnO, Zn.sub.2SO.sub.4, WO.sub.3, In.sub.2O.sub.3, SrTiO.sub.3, Nb.sub.2O.sub.5, BaSnO.sub.3, Y:SnO.sub.2, Cu:NiO.sub.x, C.sub.60, C.sub.70, PC.sub.61BM, PC.sub.71BM, or fullerene.
6. The method of any of the preceding claims, wherein the material of the functionalized material comprises one or more of an a metal oxide, a doped metal oxide, TiO.sub.2, SnO.sub.2, NiO.sub.x, CuO, ZnO, Zn.sub.2SO.sub.4, WO.sub.3, In.sub.2O.sub.3, SrTiO.sub.3, Nb.sub.2O.sub.5, BaSnO.sub.3, Y:SnO.sub.2, Cu:NiO.sub.x, C.sub.60, C.sub.70, PC.sub.61BM, PC.sub.71BM, or fullerene.
7. The method of any of the preceding claims, wherein the material of the functionalized material comprises one or more of TiO.sub.2, SnO.sub.2, NiO.sub.x, CuO, ZnO, Zn.sub.2SO.sub.4, WO.sub.3, In.sub.2O.sub.3, SrTiO.sub.3, Nb.sub.2O.sub.5, BaSnO.sub.3, Y:SnO.sub.2, or Cu:NiO.sub.x.
8. The method of any of the preceding claims, wherein the material of the functionalized material comprises one or more of SnO.sub.2, NiO.sub.x, Y:SnO.sub.2, or Cu:NiO.sub.x.
9. The method of any of the preceding claims, wherein the one or more functionalizing compounds is one or more of:
(1)
R.sub.1aCOOH (I), or salts thereof, where R.sub.1a is substituted or unsubstituted alkyl;
(2)
R.sub.2aOCS.sub.2.sup.M.sup.+.sub.2a (II), where R.sub.2a is substituted or unsubstituted alkyl, and M.sup.+.sub.2a is a cation; ##STR00011## where X.sub.3 is an anion; R.sub.3a, R.sub.3c, R.sub.3d, and R.sub.3e is the same or different and is H, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl; R.sub.3b is H, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted Lewis base, quaternary nitrogen salts, carboxylates, xanthates, alkoxides, or thiolates; ##STR00012## where X.sub.4 is an anion; R.sub.4a, R.sub.4c, R.sub.4d, R.sub.4e, R.sub.4f, and R.sub.4g is the same or different and is H, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl; R.sub.4b is H, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, substituted or unsubstituted Lewis base, quaternary nitrogen salts, carboxylates, xanthates, alkoxides, or thiolates; ##STR00013## where R.sub.5a, R.sub.5b, and R.sub.5c is the same or different and is H, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl; ##STR00014## where R.sub.6b, R.sub.6c, and R.sub.6d is the same or different and is H, substituted or unsubstituted alkyl, or substituted or unsubstituted aryl; R.sub.6a is H, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, where the R.sub.6a substituted alkyl is optionally substituted with one or more substituted or unsubstituted Lewis bases, quaternary nitrogen salts, carboxylates, xanthates, alkoxides, or thiolates, where the R.sub.6a substituted aryl is optionally substituted with one or more substituted or unsubstituted Lewis bases, quaternary nitrogen salts, carboxylates, xanthates, alkoxides, or thiolates; or
(7)
R.sub.7aNHCS.sub.2.sup.M.sup.+.sub.7a (VII), where R.sub.7a is a substituted or unsubstituted alkyl and M.sup.+.sub.2a is a cation.
10. The method of any of the preceding claims, wherein R.sub.1a is a substituted or unsubstituted C.sub.1-C.sub.8 alkyl, methyl, ethyl, propyl, or butyl.
11. The method of any of the preceding claims, wherein R.sub.2a is a substituted or unsubstituted alkyl C.sub.1-C.sub.36 alkyl, methyl, ethyl, propyl, butyl, dodecyl, or octadecyl; M.sup.+.sub.2a is Na.sup.+, K.sup.+, or Li.sup.+; or a combination thereof.
12. The method of any of the preceding claims, wherein X.sub.3 is Cl.sup., Br.sup., I.sup., BF.sub.4.sup., PF.sub.6.sup., or CF.sub.3SO.sub.3.sup.; R.sub.3a, R.sub.3c, R.sub.3d, and R.sub.3e is the same or different and is H, substituted or unsubstituted C.sub.1-C.sub.8 alkyl, or substituted or unsubstituted phenyl; R.sub.3b is H, substituted or unsubstituted C.sub.1-C.sub.8 alkyl, substituted or unsubstituted phenyl, C(O)H, C(O)OH, C(O)NHR.sub.3f, CH.sub.2OR.sub.3f, CH.sub.2NHR.sub.3f, quaternary nitrogen salts, carboxylates, xanthates, alkoxides, or thiolates, R.sub.3f is H, substituted or unsubstituted C.sub.1-C.sub.8 alkyl; or a combination thereof.
13. The method of any of the preceding claims, wherein X.sub.4 is Cl.sup., Br.sup., I.sup., BF.sub.4.sup., PF.sub.6.sup., or CF.sub.3SO.sub.3.sup.; R.sub.4a, R.sub.4c, R.sub.4d, R.sub.4e, R.sub.4f, and R.sub.4g is the same or different and is H, substituted or unsubstituted C.sub.1-C.sub.8 alkyl, or substituted or unsubstituted phenyl; R.sub.4b is H, substituted or unsubstituted C.sub.1-C.sub.8 alkyl, substituted or unsubstituted phenyl, C(O)H, C(O)OH, C(O)NHR.sub.4h, CH.sub.2OR.sub.4h, CH.sub.2NHR.sub.4h, quaternary nitrogen salts, carboxylates, xanthates, alkoxides, or thiolates, R.sub.4h is H, substituted or unsubstituted C.sub.1-C.sub.8 alkyl; or a combination thereof.
14. The method of any of the preceding claims, wherein R.sub.5a, R.sub.5b, and R.sub.5c is the same or different and is H, substituted or unsubstituted C.sub.1-C.sub.8 alkyl, or substituted or unsubstituted phenyl.
15. The method of any of the preceding claims, wherein R.sub.6b, R.sub.6c, and R.sub.6d is the same or different and is H, substituted or unsubstituted C.sub.1-C.sub.8 alkyl, or substituted or unsubstituted phenyl; R.sub.6a is H, substituted or unsubstituted C.sub.1-C.sub.8 alkyl, substituted or unsubstituted phenyl, where the R.sub.6a substituted alkyl is optionally substituted with one or more C(O)H, C(O)OH, C(O)NHR.sub.6e, CH.sub.2OR.sub.6e, CH.sub.2NHR.sub.6e, quaternary nitrogen salts, carboxylates, xanthates, alkoxides, or thiolates, where the R.sub.6a substituted aryl is optionally substituted with one or more C(O)H, C(O)OH, C(O)NHR.sub.6e, CH.sub.2OR.sub.6e, CH.sub.2NHR.sub.6e, quaternary nitrogen salts, carboxylates, xanthates, alkoxides, or thiolates, R.sub.6e is H, substituted or unsubstituted C.sub.1-C.sub.8 alkyl; or a combination thereof.
16. The method of any of the preceding claims, wherein R.sub.7a is a substituted or unsubstituted alkyl C.sub.1-C.sub.36 alkyl, methyl, ethyl, propyl, butyl, dodecyl, or octadecyl; M.sup.+.sub.7a is Na.sup.+, K.sup.+, or Li.sup.+; or a combination thereof.
17. The method of any of the preceding claims, wherein formula (IIIb) is ##STR00015##
18. The method of any of the preceding claims, wherein formula (V) is selected from triarylamines (TAA), substituted TAA, triphenylamine, substituted triphenylamines, triethylamine and substituted triethylamines.
19. The method of any of the preceding claims, wherein the functionalized material comprises one or more of a metal oxide, a doped metal oxide, TiO.sub.2, SnO.sub.2, NiO.sub.x, CuO, ZnO, Zn.sub.2SO.sub.4, WO.sub.3, In.sub.2O.sub.3, SrTiO.sub.3, Nb.sub.2O.sub.5, BaSnO.sub.3, Y:SnO.sub.2, Cu:NiO.sub.x, C.sub.60, C.sub.70, PC.sub.61BM, PC.sub.71BM, or fullerene, where each is independently functionalized with (i) one or more of formula (I) or salts thereof, where R.sub.1a is C.sub.1-C.sub.4 alkyl, (ii) one or more of formula (II), where R.sub.2a is C.sub.1-C.sub.27 alkyl and M.sup.+.sub.2a is Na.sup.+, K.sup.+, or Li.sup.+, (iii) triethylamine, or (iv) a combination thereof.
20. The method of any of the preceding claims, wherein the functionalized material comprises one or more of a metal oxide, a doped metal oxide, TiO.sub.2, SnO.sub.2, NiO.sub.x, CuO, ZnO, Zn.sub.2SO.sub.4, WO.sub.3, In.sub.2O.sub.3, SrTiO.sub.3, Nb.sub.2O.sub.5, BaSnO.sub.3, C.sub.60, C.sub.70, PC.sub.61BM, PC.sub.71BM, or fullerene, where each is independently functionalized with one or more of formula (I) or salts thereof, where R.sub.1a is C.sub.1-C.sub.4 alky.
21. The method of any of the preceding claims, wherein the functionalized material comprises one or more of TiO.sub.2, ZnO, Y:SnO.sub.2, Cu:NiO.sub.x, NiO.sub.x, or SnO.sub.2 where each is independently functionalized with acetate, propionate, triethylamine, Na C.sub.18 alkyl xanthate, Na C.sub.12 alkyl xanthate, or a combination thereof.
22. The method of any of the preceding claims, wherein the functionalized material comprises one or more of TiO.sub.2, ZnO, NiO.sub.x, or SnO.sub.2 where each is independently functionalized with one or both of acetate or propionate.
23. The method of any of the preceding claims, wherein the solvent comprises a protic solvent, an anhydrous protic solvent, anhydrous methanol, anhydrous ethanol, anhydrous isopropanol, anhydrous C.sub.1-10 alcohol, THF, dimethyl ether, diethyl ether, an anhydrous ether, an ether, chlorobenzene (CB), or a combination thereof.
24. The method of any of the preceding claims, wherein the depositing step is performed by one or more of blade coating, spin coating, slot die, gravure, flexo, spray, or inkjet.
25. The method of any of the preceding claims, wherein the depositing step is performed by blade coating.
26. The method of any of the preceding claims, wherein the heating step comprises annealing or intense pulsed light (IPL).
27. The method of any of the preceding claims, wherein the heating step comprises heating at about 80 C. to about 120 C. for about 5 to about 20 minutes.
28. The method of any of the preceding claims, wherein the heating step removes some or all of the one or more functionalizing compounds.
29. The method of any of the preceding claims, wherein the removing step occurs.
30. The method of any of the preceding claims, wherein the removing step occurs by heat or by intense pulsed light (IPL).
31. The method of any of the preceding claims, wherein (i) the heating step removes some of the one or more functionalizing compounds and (ii) the removing step occurs, and further removes some of or all of the remainder of the one or more functionalizing compounds.
32. The method of any of the preceding claims, wherein the perovskite layer comprises one or more of CH.sub.3NH.sub.3PbX.sub.3, CH.sub.3NH.sub.3PbI.sub.3, H.sub.2NCHNH.sub.2PbX.sub.3, CH.sub.3NH.sub.3SnX.sub.3, or Cs.sub.a(CH.sub.5NH.sub.3).sub.b(CH.sub.3NH.sub.3).sub.cPbI.sub.3(1y)Br.sub.3y where X is a halogen which can be the same or different between or within each formula, a is about 0 to about 0.5, b is about 0 to about 0.8, c is about 0 to about 0.8, and y is about 0 to about 1.
33. The method of any of the preceding claims, wherein the PSC is a p-i-n type device.
34. The method of any of the preceding claims, wherein the PSC is an n-i-p type device.
35. The method of any of the preceding claims, wherein the perovskite layer is part of a structure that further comprises one or more of an anode; a hole transport layer (HTL); or a cathode.
36. The method of any of the preceding claims, wherein the perovskite layer is part of a structure that further comprises one or more of an anode; an electron transport layer (ETL); or a cathode.
37. The method of any of the preceding claims, wherein the method further comprises adding a cathode.
38. The method of any of the preceding claims, wherein the method further comprises adding a cathode and the method for adding the cathode is screen printing, thermal evaporation, sputtering, or atomic layer deposition.
39. The method of any of the preceding claims, wherein the method further comprises adding a cathode and the method for adding the cathode is thermal evaporation.
40. The method of any of the preceding claims, wherein the method further comprises adding a cathode and the cathode is Fe, C, Ni, Pt, Ag, Al, or Cu.
41. The method of any of the preceding claims, wherein the method further comprises adding a cathode and the cathode is Ag, Al, or Cu.
42. The method of any of the preceding claims, wherein the PSC has an open circuit voltage (Voc) of from about 0.7 V to about 1.3V.
43. The method of any of the preceding claims, wherein the PSC has fill factor (FF) of from about 35% to about 80%.
44. The method of any of the preceding claims, wherein the PSC has a current density (J.sub.sc) of from about 10 mA/cm.sup.2 to about 25 mA/cm.sup.2.
45. The method of any of the preceding claims, wherein the PSC has a Power Conversion Efficiency (PCE) of from about 4% to about 20%.
46. The method of any of the preceding claims, wherein the PSC is a flexible PSC.
47. The PSC made according to any of the preceding claims.
48. The PSC of claim 47, comprising an anode; a hole transport layer (HTL); an electron transport layer (ETL) and a perovskite layer, prepared according to any of claims 1 to 46; and a cathode.
49. The PSC of claim 48, wherein the anode is ITO/glass or FTL/glass.
50. The PSC of claim 48 or claim 49, wherein the HTL is NiO.sub.x, PTAA or PTAA/PFN.
51. The PSC of any of claims 48-50, wherein the perovskite layer is one or more of CH.sub.3NH.sub.3PbX.sub.3, CH.sub.3NH.sub.3PbI.sub.3, H.sub.2NCHNH.sub.2PbX.sub.3, or CH.sub.3NH.sub.3SnX.sub.3, where X is a halogen which can be the same or different between or within each formula.
52. The PSC of any of claims 48-51, wherein the cathode is Fe, C, Ni, Pt, Ag, Al, or Cu.
53. The PSC of any of claims 48-52, wherein the cathode is Ag, Al, or Cu.
54. The PSC of claim 47, comprising an anode; an ETL; an HTL and a perovskite layer, prepared according to any of claims 1 to 46; and a cathode.
55. The PSC of claim 54, wherein the anode is ITO/glass.
56. The PSC of claim 54 or claim 55, wherein the ETL is SnO.sub.2, TiO.sub.2, or ZnO.
57. The PSC of any of claims 54-56, wherein the perovskite layer is one or more of CH.sub.3NH.sub.3PbX.sub.3, CH.sub.3NH.sub.3PbI.sub.3, H.sub.2NCHNH.sub.2PbX.sub.3, or CH.sub.3NH.sub.3SnX.sub.3, where X is a halogen which can be the same or different between or within each formula.
58. The PSC of any of claims 54-57, wherein the cathode is Fe, C, Ni, Pt, Ag, Al, or Cu.
59. The PSC of any of claims 54-58, wherein the cathode is Ag, Al, or Cu.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
[0030] The following drawings form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these drawings in combination with the description of specific embodiments presented herein.
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DETAILED DESCRIPTION
[0056] While embodiments encompassing the general inventive concepts may take diverse forms, various embodiments will be described herein, with the understanding that the present disclosure is to be considered merely exemplary, and the general inventive concepts are not intended to be limited to the disclosed embodiments.
[0057] Some embodiments of the invention include inventive methods for preparing perovskite solar cells (PSCs). In certain embodiments, the method comprises dissolving a functionalized material (e.g., a material that is functionalized with one or more functionalizing compounds) in a solvent, depositing a deposit composition on a perovskite layer where the deposit composition comprises the dissolved functionalized material, heating the deposit composition, and optionally removing some or all of the one or more functionalizing compounds from the deposit composition. Additional embodiments of the invention are also disclosed herein.
[0058] As used herein (unless otherwise specified), the term alkyl means a monovalent, straight or branched hydrocarbon chain. For example, the terms C.sub.1-C.sub.7 alkyl or C.sub.1-C.sub.4 alkyl refer to straight-or branched-chain saturated hydrocarbon groups having from 1 to 7 (e.g., 1, 2, 3, 4, 5, 6, or 7), or 1 to 4 (e.g., 1, 2, 3, or 4), carbon atoms, respectively. Examples of C.sub.1-C.sub.7 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, n-pentyl, s-pentyl, n-hexyl, and n-septyl. Examples of C.sub.1-C.sub.4 alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, and t-butyl.
[0059] As used herein (unless otherwise specified), the term alkoxy means any of the above alkyl groups which is attached to the remainder of the molecule by an oxygen atom (alkyl-O). Examples of alkoxy groups include, but are not limited to, methoxy (sometimes shown as MeO), ethoxy, isopropoxy, propoxy, and butyloxy.
[0060] As used herein (unless otherwise specified), the term aryl means a monovalent, monocyclic or bicyclic, 5, 6, 7, 8, 9, 10, 11, or 12 membered aromatic hydrocarbon group, when unsubstituted. Examples of aryl groups include, but are not limited to, phenyl, naphthyl, tolyl, and xylyl. For a bicyclic aryl that is designated as substituted, one or both rings can be substituted.
[0061] As used herein (unless otherwise specified), the term halogen means monovalent Cl, F, Br, or I.
[0062] As used herein (unless otherwise specified), the term hetero atom means an atom selected from nitrogen atom, oxygen atom, or sulfur atom.
[0063] As used herein (unless otherwise specified), the terms hydroxy or hydroxyl indicates the presence of a monovalent OH group.
[0064] As used herein (unless otherwise specified), the term Lewis base means any chemical species that has a filled orbital containing an electron pair which is not involved in bonding but may form a dative bond (i.e., a two-center, two-electron covalent bond in which the two electrons derive from the same atom) with another chemical (e.g., a chemical that has an empty orbital capable of accepting an electron pair). Some Lewis bases can be conventional amines (e.g., ammonia and alkyl amines) or pyridine and its derivatives. Some classes of Lewis bases are (a) amines (e.g., NR.sub.3 where R is independently H, alkyl, or aryl) (b) phosphines (e.g., PR.sub.3 where R is independently alkyl or aryl), or (c) compounds of O, S, Se and Te in oxidation state 2, (e.g., water, ethers, or ketones). Other examples of Lewis bases include (a) simple anions, such as H.sup. and F.sup., (b) lone-pair-containing species, such as H.sub.2O, NH.sub.3, HO.sup., and CH.sub.3.sup., (c) complex anions, such as sulfate, and (d) electron-rich -systems, such as ethyne, ethene, and benzene. Other examples of Lewis bases include Et.sub.3N, quinuclidine, pyridine, acetonitrile, Et.sub.2O, THF, acetone, EtOAc, DMA, DMSO, tetrahydrothiophene, and trimethylphosphine. Lewis bases can be monovalent moieties. Lewis bases can be substituted or unsubstituted.
[0065] As used herein (unless otherwise specified), the term substituted (e.g., as in substituted alkyl) means that one or more hydrogen atoms of a chemical group (with one or more hydrogen atoms) can be replaced by one or more non-hydrogen substituents selected from the specified options. The replacement can occur at one or more positions. The term optionally substituted means that one or more hydrogen atoms of a chemical group (with one or more hydrogen atoms) can be, but is not required to be substituted. Non-hydrogen substituents include but are not limited to halogen (e.g., F, Cl, Br, or I), hydroxy (OH), methanoyl (COH), COCH.sub.3, carboxy (CO.sub.2H), ethynyl (CCH), cyano (CN), sulfo (SO.sub.3H), methyl, ethyl, perfluorinated methyl, perfluorinated ethyl, amines, alcohols, ethers, thiols, thioethers, amides, Lewis bases, quaternary nitrogen salts, carboxylates, xanthates, alkoxides, thiolates, aldehydes, C(O)OH, C(O)NHR, CH.sub.2OR, or CH.sub.2NHR, where R can be H, unsubstituted alkyl (e.g., C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, or C.sub.8 alkyl) or alkyl (e.g., C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, or C.sub.8 alkyl) substituted (e.g., with one or more of halogen (e.g., F, Cl, Br, or I), hydroxy (OH), methanoyl (COH), COCH.sub.3, carboxy (CO.sub.2H), ethynyl (CCH), cyano (CN), sulfo (SO.sub.3H), methyl, ethyl, perfluorinated methyl, perfluorinated ethyl, amines, alcohols, ethers, thiols, thioethers, amides, or aldehydes).
Methods for Preparing Perovskite Solar Cells (PSCs)
[0066] Some embodiments of the invention include methods for preparing a Perovskite Solar Cell (PSC), as disclosed herein. In certain embodiments, the method comprises (a) dissolving a functionalized material in a solvent, where the functionalized material is a material that is functionalized with one or more functionalizing compounds, (b) depositing (e.g., layering) a deposit composition (e.g., an ink) on a perovskite layer where the deposit composition comprises the dissolved functionalized material; (c) heating the deposit composition on the perovskite layer; and (d) optionally removing some or all of the one or more functionalizing compounds.
[0067] In some embodiments, the material of the functionalized material can be any suitable material. In certain embodiments, the material of the functionalized material can be one or more of an organic material, a metal oxide, TiO.sub.2, SnO.sub.2, NiO.sub.x, CuO, ZnO, Zn.sub.2SO.sub.4, WO.sub.3, In.sub.2O.sub.3, SrTiO.sub.3, Nb.sub.2O.sub.5, BaSnO.sub.3, C.sub.60, C.sub.70, PC.sub.61BM, PC.sub.71BM, or fullerene. NiO.sub.x refers to NiO (Ni.sup.2+), Ni.sub.2O.sub.3 (Ni.sup.3+) and/or mixtures of NiO and Ni.sub.2O.sub.3. In some embodiments, the material of the functionalized material can be one or more of an organic material, a metal oxide, a doped metal oxide, TiO.sub.2, SnO.sub.2, NiO.sub.x, CuO, ZnO, Zn.sub.2SO.sub.4, WO.sub.3, In.sub.2O.sub.3, SrTiO.sub.3, Nb.sub.2O.sub.5, BaSnO.sub.3, Y:SnO.sub.2, Cu:NiO.sub.x, C.sub.60, C.sub.70, PC.sub.61BM, PC.sub.71BM, or fullerene. In other embodiments, the material can be doped using one or more of any suitable doping substances (e.g., Zr, Sb, Li, Mg, Y, Nb, Cu, or Mo). A material that is doped can be but is not limited to Cu:NiO.sub.x or Y:SnO.sub.2. In some embodiments, the material can be SnO.sub.2, NiO.sub.x, Cu:NiO.sub.x or Y:SnO.sub.2. In some embodiments, the material (e.g., the material that is doped) can be functionalized (e.g., the material is bonded to one or more of a functionalizing compound using covalent and/or ionic bonds) with one or more functionalizing compounds (e.g., one or more suitable functionalizing compounds). In other embodiments, the material (e.g., the material that is doped) can be functionalized (e.g., the material is bonded to the one or more functionalizing compounds using covalent bonds, ionic bonds, or both) with one or more of the following the functionalizing compounds (e.g., one or more selected from Formulas (I), (II), (IIIa), (IIIb), (IVa), (IVb), (V), (VI), or (VI)):
(1)
R.sub.1aCOOH (I),
or salts thereof (e.g., where the cation can be, for example, Na.sup.+, K.sup.+, Li.sup.+, Mg.sup.2+, Ca.sup.2+, or any suitable cation), where R.sub.1a can be substituted or unsubstituted alkyl (e.g., C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, or C.sub.8 alkyl, or methyl, ethyl, propyl, or butyl);
(2)
R.sub.2aOCS.sub.2.sup.M.sup.+.sub.2a (II),
where R.sub.2a can be substituted or unsubstituted alkyl (e.g., C.sub.1-C.sub.18 alkyl, C.sub.1-C.sub.27 alkyl, C.sub.1-C.sub.36 alkyl, or C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, C.sub.8, C.sub.9, C.sub.10, C.sub.11, C.sub.12, C.sub.13, C.sub.14, C.sub.15, C.sub.16, C.sub.17, C.sub.18, C.sub.19, C.sub.20, C.sub.21, C.sub.22, C.sub.23, C.sub.24, C.sub.25, C.sub.26, C.sub.27, C.sub.28, C.sub.29, C.sub.30, C.sub.31, C.sub.32, C.sub.33, C.sub.34, C.sub.35, or C.sub.36 alkyl or, methyl, ethyl, propyl, butyl, dodecyl, or octadecyl), and M.sup.+.sub.2a can be any suitable cation (e.g., Na.sup.+, K.sup.+, or Li.sup.+);
##STR00006##
(e.g., imidazoles and imidazolium salts thereof) where X.sub.3 can be Cl.sup., Br.sup., I.sup., BF.sub.4.sup., PF.sub.6.sup., CF.sub.3SO.sub.3.sup., or any suitable anion. R.sub.3a, R.sub.3c, R.sub.3d, and R.sub.3e can be the same or different and can be H, substituted or unsubstituted alkyl (e.g., C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, or C.sub.8 alkyl), or substituted or unsubstituted aryl (e.g., phenyl). R.sub.3b can be H, substituted or unsubstituted alkyl (e.g., C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, or C.sub.8 alkyl), substituted or unsubstituted aryl (e.g., phenyl), substituted or unsubstituted Lewis base (e.g. with amines, alcohols, ethers, thiols, thioethers, amides, or aldehydes, such as C(O)H, C(O)OH, C(O)NHR.sub.3f, CH.sub.2OR.sub.3f, or CH.sub.2NHR.sub.3f) or charged functional groups (e.g. quaternary nitrogen salts, carboxylates, xanthates, alkoxides, or thiolates). R.sub.3f can be H, substituted or unsubstituted alkyl (e.g., C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, or C.sub.8 alkyl). Some examples of formula (IIIb) include, but are not limited to
##STR00007##
where R.sub.3c is H or unsubstituted alkyl (e.g., C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, or C.sub.8 alkyl), R.sub.3f is H or unsubstituted alkyl (e.g., C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, or C.sub.8 alkyl), and X.sub.3 is Cl.sup., Br.sup., I.sup., BF.sub.4.sup., PF.sub.6.sup., or CF.sub.3SO.sub.3.sup.;
##STR00008##
(e.g., benzimidazoles and benzimidazolium salts thereof). X.sub.4 can be Cl.sup., Br.sup., I.sup., BF.sub.4.sup., PF.sub.6.sup., CF.sub.3SO.sub.3.sup., or any suitable anion. R.sub.4a, R.sub.4c, R.sub.4d, R.sub.4e, R.sub.4f, and R.sub.4g can be the same or different and can be H, substituted or unsubstituted alkyl (e.g., C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, or C.sub.8 alkyl), or substituted or unsubstituted aryl (e.g., phenyl). R.sub.4b can be H, substituted or unsubstituted alkyl (e.g., C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, or C.sub.8 alkyl), substituted or unsubstituted aryl (e.g., phenyl), substituted Lewis bases (e.g. with amines, alcohols, ethers, thiols, thioethers, amides, or aldehydes, such as C(O)H, C(O)OH, C(O)NHR.sub.4h, CH.sub.2OR.sub.4h, or CH.sub.2NHR.sub.4h) or charged functional groups (e.g. quaternary nitrogen salts, carboxylates, xanthates, alkoxides, or thiolates). R.sub.4h can be H, substituted or unsubstituted alkyl (e.g., C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, or C.sub.8 alkyl);
##STR00009##
R.sub.5a, R.sub.5b, and R.sub.5c can be the same or different and can be H, substituted or unsubstituted alkyl (e.g., C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, or C.sub.8 alkyl), or substituted or unsubstituted aryl (e.g., phenyl). Examples of formula (V) include triarylamines (TAA), substituted TAA, triphenylamine, substituted triphenylamines, triethylamine and substituted triethylamines;
##STR00010##
(such as 2-pyrrolidinones) R.sub.6b, R.sub.6c, and R.sub.6d can be the same or different and can be H, substituted or unsubstituted alkyl (e.g., C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, or C.sub.8 alkyl), or substituted or unsubstituted aryl (e.g., phenyl). R.sub.6a can be H, substituted or unsubstituted alkyl (e.g., C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, or C.sub.8 alkyl), substituted or unsubstituted aryl (e.g., phenyl). R.sub.6a substituted alkyl can be optionally substituted with one or more with Lewis bases (e.g. with amines, alcohols, ethers, thiols, thioethers, amides, or aldehydes, such as C(O)H, C(O)OH, C(O)NHR.sub.6e, CH.sub.2OR.sub.6e, or CH.sub.2NHR.sub.6e) or charged functional groups (e.g. quaternary nitrogen salts, carboxylates, xanthates, alkoxides, or thiolates). R.sub.6a substituted aryl can be optionally substituted with one or more with Lewis bases (e.g. with amines, alcohols, ethers, thiols, thioethers, amides, or aldehydes, such as C(O)H, C(O)OH, C(O)NHR.sub.6e, CH.sub.2OR.sub.6e, or CH.sub.2NHR.sub.6e) or charged functional groups (e.g. quaternary nitrogen salts, carboxylates, xanthates, alkoxides, or thiolates). R.sub.6e can be H, substituted or unsubstituted alkyl (e.g., C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, or C.sub.8 alkyl); or
(7)
R.sub.7aNHCS.sub.2.sup.M.sup.+.sub.7a (VII),
where R.sub.7a can be substituted or unsubstituted alkyl (e.g., C.sub.1-C.sub.18 alkyl, C.sub.1-C.sub.27 alkyl, C.sub.1-C.sub.36 alkyl, or C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, C.sub.8, C.sub.9, C.sub.10, C.sub.11, C.sub.12, C.sub.13, C.sub.14, C.sub.15, C.sub.16, C.sub.17, C.sub.18, C.sub.19, C.sub.20, C.sub.21, C.sub.22, C.sub.23, C.sub.24, C.sub.25, C.sub.26, C.sub.27, C.sub.28, C.sub.29, C.sub.30, C.sub.31, C.sub.32, C.sub.33, C.sub.34, C.sub.35, or C.sub.36 alkyl or, methyl, ethyl, propyl, butyl, dodecyl, or octadecyl), and M.sup.+.sub.7a can be any suitable cation (e.g., Na.sup.+, K.sup.+, or Li.sup.+).
[0068] In certain embodiments, the functionalized material comprises one or more of an organic material, a metal oxide, TiO.sub.2, SnO.sub.2, NiO.sub.x, CuO, ZnO, Zn.sub.2SO.sub.4, WO.sub.3, In.sub.2O.sub.3, SrTiO.sub.3, Nb.sub.2O.sub.5, BaSnO.sub.3, C.sub.60, C.sub.70, PC.sub.61BM, PC.sub.71BM, or fullerene, where each can be independently functionalized with one or more of RCOOH, where R can be C.sub.1-C.sub.4 alky or salts thereof. In still other embodiments, the functionalized material comprises one or more of a metal oxide, a doped metal oxide, TiO.sub.2, SnO.sub.2, NiO.sub.x, CuO, ZnO, Zn.sub.2SO.sub.4, WO.sub.3, In.sub.2O.sub.3, SrTiO.sub.3, Nb.sub.2O.sub.5, BaSnO.sub.3, Y:SnO.sub.2, Cu:NiO.sub.x, C.sub.60, C.sub.70, PC.sub.61BM, PC.sub.71BM, or fullerene, where each is independently functionalized with (i) one or more of formula (I) or salts thereof, where R.sub.1a is C.sub.1-C.sub.4 alkyl, (ii) one or more of formula (II), where R.sub.2a is C.sub.1-C.sub.27 alkyl and M.sup.+.sub.2a is Na.sup.+, K.sup.+, or Li.sup.+, (iii) triethylamine, or (iv) a combination thereof. In yet other embodiments, the functionalized material comprises one or more of a metal oxide, a doped metal oxide, TiO.sub.2, SnO.sub.2, NiO.sub.x, CuO, ZnO, Zn.sub.2SO.sub.4, WO.sub.3, In.sub.2O.sub.3, SrTiO.sub.3, Nb.sub.2O.sub.5, BaSnO.sub.3, C.sub.60, C.sub.70, PC.sub.61BM, PC.sub.71BM, or fullerene, where each is independently functionalized with one or more of formula (I) or salts thereof, where R.sub.1a is C.sub.1-C.sub.4 alky. In certain embodiments, the functionalized material comprises one or more of TiO.sub.2, ZnO, Y:SnO.sub.2, Cu:NiO.sub.x, NiO.sub.x, or SnO.sub.2 where each is independently functionalized with acetate, propionate, triethylamine, Na C.sub.18 alkyl xanthate, Na C.sub.12 alkyl xanthate, Na C.sub.4 xanthate, Na xanthate, or a combination thereof. In certain embodiments, the functionalized material comprises one or more of TiO.sub.2, ZnO, Y:SnO.sub.2, Cu:NiO.sub.x, NiO.sub.x, or SnO.sub.2 where each is independently functionalized with acetate, propionate, triethylamine, Na C.sub.18 alkyl xanthate, Na C.sub.12 alkyl xanthate, or a combination thereof. In other embodiments, the functionalized material comprises one or more of TiO.sub.2, ZnO, NiO.sub.x, or SnO.sub.2 where each is independently functionalized with one or both of acetate or propionate. In some embodiments, the functionalized material does not comprise NiO.sub.x functionalized with C.sub.18 acetate.
[0069] In other embodiments, the solvent comprises any suitable solvent, such as but not limited to any suitable protic solvent, any suitable anhydrous protic solvent, anhydrous methanol, anhydrous ethanol, anhydrous isopropanol, anhydrous C.sub.1, C.sub.2, C.sub.3, C.sub.4, C.sub.5, C.sub.6, C.sub.7, C.sub.8, C.sub.9, or C.sub.10 alcohol, THF, dimethyl ether, diethyl ether, any suitable anhydrous ether, any suitable ether, chlorobenzene (CB), or combinations thereof. In some embodiments, the solvent comprises anhydrous ethanol, anhydrous isopropanol, chlorobenzene (CB), or combinations thereof. In other embodiments, the solvent does not degrade (e.g., does not significantly and/or detrimentally degrade) the perovskite layer. In some embodiments, the solvent does not comprise CB. In some embodiments, the solvent does not comprise isopropanol.
[0070] In certain embodiments, the deposit composition comprises the dissolved functionalized material, where the dissolved (e.g., completely dissolved or partially dissolved) functionalized material comprises functionalized material and solvent. In some embodiments, the functionalized material can be completely dissolved in the solvent. In still other embodiments, the functionalized material can be partially dissolved (e.g., at least 80%, at least 90%, or at least 99% dissolved by weight of total functionalized material, or 99.9%, 99%, 98%, 95%, 90%, 85%, or 80% dissolved by weight of total functionalized material) in the solvent. In certain embodiments, the concentration of the functionalized material in the deposit composition can be any suitable concentration (e.g., from 0.01 to 90.0, from 0.01 to 50.0, from 0.01 to 10.0, from 0.1 to 5.0, from 0.5 to 3.0% (m/v), or 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.5, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 20.0, 30.0, 40.0, 50.0, 60.0, 70.0, 80.0, or 90.0% (m/v) (or g/100 mL)). In other embodiments, the concentration of the functionalized material in the deposit composition can be any suitable concentration (e.g., from 0.01 to 99.9, from 0.01 to 50.0, from 0.01 to 10.0, from 0.1 to 5.0, from 0.5 to 3.0 wt/wt %, or 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.5, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 20.0, 30.0, 40.0, 50.0, 60.0, 70.0, 80.0, 90.0, 95.0, 99.0, or 99.9 wt/wt %, based on the total weight of the deposit composition). In yet other embodiments, the deposit composition (e.g., an ink) further comprises one or more of any suitable doping substances (e.g., Zr, Sb, Li, Mg, Y, Nb, Cu or Mo). As described herein, the deposit composition can comprise a functionalized material; the functionalized material can be a material that is functionalized with one or more functionalizing compounds. In other embodiments, the material encompasses material that is doped using one or more of any suitable doping substances (e.g., Zr, Sb, Li, Mg, Y, Nb, Cu or Mo). A material that is doped can be but is not limited to Cu:NiO.sub.x or Y:SnO.sub.2. In some embodiments, the material (e.g., the doped material) can be functionalized (e.g., the material is bonded to the one or more functionalizing compounds using covalent and/or ionic bonds) with one or more suitable functionalizing compounds. In some embodiments, the deposit composition does not comprise NiO.sub.x functionalized with C.sub.18 acetate dissolved in CB.
[0071] In other embodiments, the depositing can be performed by one or more of any suitable depositing method. In yet other embodiments, the depositing can be performed by one or more of blade coating, spin coating, pulsed laser deposition, electron beam evaporation, spray pyrolysis, co-sputtering, atomic layer deposition, slot die, gravure, flexo, spray, or inkjet. In other embodiments, the depositing can be performed by one or more of blade coating, spin coating, slot die, gravure, flexo, spray, or inkjet. In still other embodiments, the depositing can be performed by blade coating. In certain embodiments, the deposit composition is layered on the perovskite layer. In some embodiments, the deposit composition is layered on the perovskite layer so that the perovskite layer is at least partially covered by the deposit composition or is completely covered by the deposit composition. In other embodiments, the solvent during depositing does not degrade (e.g., does not significantly and/or detrimentally degrade) the perovskite layer. In certain embodiments, the depositing does not use vacuum technology such as, but not limited to, atomic layer deposition, sputtering, or evaporation.
[0072] In some embodiments, the heating can be accomplished using any suitable heating method, such as but not limited to, hot plates, ovens (e.g., convective ovens), or intense pulsed light (IPL) (examples of IPL details and methods are disclosed in U.S. Pat. No. 10,950,794 issued Mar. 16, 2021, which is herein incorporated by reference in its entirety). In still other embodiments, the heating comprises annealing (e.g., by IPL). In still other embodiments, the heating comprises heating by intense pulsed light (IPL). In yet other embodiments, the heating comprises heating (e.g., using hot plates, ovens (e.g., convective ovens), or IPL) at about 80 C. to about 120 C. (e.g., about 80 C., about 90 C., about 100 C., about 110 C., or about 120 C.,) for about 5 to about 20 minutes (e.g., about 5, about 8, about 10, about 12, about 15, or about 20 minutes). In yet other embodiments, the heating can heat other layers of the PSC (or the PSC in the making). In still other embodiments, the heating does not significantly heat other layers of the PSC (or the PSC in the making). In certain embodiments, the heating can remove some or all of the one or more functionalizing compounds. In other embodiments, removing some of the one or more functionalizing compounds occurs during the heating step and removing more (e.g., removing the remainder of the the one or more functionalizing compounds, leftover from the heating step) of the the one or more functionalizing compounds occurs during removing step (e.g., as described below). In some instances, the heating does not remove any of the one or more functionalizing compounds. In other embodiments, the solvent during heating does not degrade (e.g., does not significantly and/or detrimentally degrade) the perovskite layer.
[0073] In some embodiments, the removing step occurs, can be any suitable method for removing some or all of the one or more functionalizing compounds, and removes some or all of the one or more functionalizing compounds (e.g., removing acetate or propionate). In certain embodiments, the removing some or all of the one or more functionalizing compounds occurs by intense pulsed light (IPL), by further heating (e.g., using hot plates, ovens (e.g., convective ovens), or IPL) (e.g., heating comprises heating at about 80 C. to about 120 C. (e.g., about 80 C., about 90 C., about 100 C., about 110 C., or about 120 C.,) for about 5 to about 20 minutes (e.g., about 5, about 8, about 10, about 12, about 15, or about 20 minutes)), or both. In other embodiments, the solvent during removing does not degrade (e.g., does not significantly and/or detrimentally degrade) the perovskite layer.
[0074] In certain embodiments, the perovskite layer can be any suitable perovskite layer (e.g., a perovskite film). In other embodiments, the perovskite layer can comprise one or more of CH.sub.3NH.sub.3PbX.sub.3, CH.sub.3NH.sub.3PbI.sub.3, H.sub.2NCHNH.sub.2PbX.sub.3, CH.sub.3NH.sub.3SnX.sub.3, or Cs.sub.a(CH.sub.5NH.sub.3).sub.b(CH.sub.3NH.sub.3).sub.c(PbI.sub.3(1y)Br.sub.3y where X is a halogen (e.g., iodide, bromide or chloride) which can be the same or different between or within each formula, a can be about 0 to about 0.5, b can be about 0 to about 0.8, c can be about 0 to about 0.8 and y can be about 0 to about 1. Other suitable perovskite layers (e.g., perovskite films) include those disclosed in U.S. Pat. No. 10,950,794 issued Mar. 16, 2021, which is herein incorporated by reference in its entirety.
[0075] In some embodiments, the PSC is a p-i-n type device. In other embodiments, the PSC is an n-i-p type device. Examples of various layers (and their methods of making them), such as HTLs or ETLs, in these devices can be found, for example in (a) Pitchaiya et al. (2020) A review on the classification of organic/inorganic/carbonaceous hole transporting materials for perovskite solar cell application Arab. J. Chem., Vol. 13, pp. 2526-2557 (which is herein incorporated by reference in its entirety) and (b) Foo et al. (2022) Recent review on electron transport layers in perovskite solar cells International Journal of Energy Research, 2022, pp. 1-11 (which is herein incorporated by reference in its entirety).
[0076] In other embodiments, the PSC is a flexible PSC. Examples of flexible PSC and their methods for making them can be found, for example, in (a) Tang et al. (2021) Recent progress of flexible perovskite solar cells Nano Today, Vol. 39, Article 101155 (which is herein incorporated by reference in its entirety) and (b) Di Giacomo (2016) Progress, challenges and perspectives in flexible perovskite solar cells Energy and Environmental Science, 2016, Vol. 9, pp. 3007-3035 (which is herein incorporated by reference in its entirety).
[0077] In certain embodiments, the perovskite layer can be part of a structure that further comprises one or more of an anode (e.g., any suitable anode such as ITO/glass or FTL/glass); a hole transport layer (HTL) (e.g., any suitable HTL, such as PTAA or NiO.sub.x); or a cathode (e.g., any suitable cathode, such as Fe, C, Ni, Pt, Ag, Al, or Cu).
[0078] In other embodiments, the perovskite layer can be part of a structure that further comprises one or more of an anode (e.g., any suitable anode such as ITO/glass or FTL/glass); an electron transport layer (ETL) (e.g., any suitable ETL, such as SnO.sub.2, Tio.sub.2, or ZnO); or a cathode (e.g., any suitable cathode, such as Fe, C, Ni, Pt, Ag, Al, or Cu).
[0079] In some embodiments, the method further comprises adding a cathode. Any suitable method of adding a cathode can be used, including but not limited to, screen printing, thermal evaporation, sputtering, or atomic layer deposition. In certain embodiments, the method of adding a cathode comprises thermal evaporation. The cathode that is added can be any suitable cathode, including but not limited to, Fe, C, Ni, Pt, Ag, Al, or Cu. In other embodiments, the cathode is Ag, Al, or Cu.
[0080] In certain embodiments, the PSC has an open circuit voltage (V.sub.OC) of from about 0.7 V to about 1.3 V or from about 0.8 V to about 1.1 V (e.g., about 0.7, about 0.8, about 0.9, about 1.0, about 1.1, about 1.2, or about 1.3 V).
[0081] In some embodiments, the PSC has a fill factor (FF) of from about 35 to about 80% or from about 39 to about 77% (e.g., about 35, about 40, about 45, about 50, about 55, about 56, about 57, about 58, about 59, about 60, about 61, about 62, about 63, about 64, about 65, about 70, about 75, or about 80%).
[0082] In certain embodiments, the PSC has a current density (J.sub.sc) of from about 10 to about 25 mA/cm.sup.2 or from about 12 to about 24 mA/cm.sup.2 (e.g., about 10, about 11, about 12, about 13, about 14, about 15, about 16, about 17, about 18, about 19, about 20, about 21, about 22, about 23, about 24, or about 25 mA/cm.sup.2).
[0083] In other embodiments, the PSC has a Power Conversion Efficiency (PCE) of from about 4 to about 20% or from about 4 to about 15% (e.g., about 4, about 5, about 6, about 7, about 8, about 9, about 10, about 11, about 12, about 13, about 14, about 15, about 16, about 17, about 18, about 19, or about 20%)
[0084] Some embodiments of the invention include a PSC made as disclosed herein (e.g., as disclosed above, as disclosed in original claim 1, or as disclosed in the Examples). In other embodiments, the PSC is a flexible PSC.
[0085] Other embodiments of the invention include a PSC (e.g., as disclosed herein) comprising a material selected from one or more of an organic material, a metal oxide, TiO.sub.2, SnO.sub.2, ZnO, NiO.sub.x, Zn.sub.2SO.sub.4, WO.sub.3, In.sub.2O.sub.3, SrTiO.sub.3, Nb.sub.2O.sub.5, BaSnO.sub.3, C.sub.60, C.sub.70, PC.sub.61BM, PC.sub.71BM, or fullerene (e.g., where the material is in an electron transport layer). In certain embodiments, the material can be functionalized according to any manner disclosed herein (e.g., as disclosed above, as disclosed in original claim 1, or as disclosed in the Examples). In some embodiments, the material comprises SnO.sub.2, functionalized SnO.sub.2 (e.g., functionalized with acetate), or both. In other embodiments, the PSC is a flexible PSC.
[0086] Other embodiments of the invention include a PSC (e.g., as disclosed herein) comprising (a) an anode (e.g., any suitable anode such as ITO/glass or FTL/glass); (b) a hole transport layer (HTL) (e.g., any suitable HTL, such as NiO.sub.x, PTAA or PTAA/PFN); (c) a perovskite layer (e.g., any suitable perovskite, such as one or more of CH.sub.3NH.sub.3PbX.sub.3, CH.sub.3NH.sub.3PbI.sub.3, H.sub.2NCHNH.sub.2PbX.sub.3, or CH.sub.3NH.sub.3SnX.sub.3, where X is a halogen (e.g., iodide, bromide or chloride) which can be the same or different between or within each formula; (d) an electron transport layer (ETL) (e.g., a material selected from an organic material, a metal oxide, TiO.sub.2, SnO.sub.2, ZnO, Zn.sub.2SO.sub.4, WO.sub.3, In.sub.2O.sub.3, SrTiO.sub.3, Nb.sub.2O.sub.5, BaSnO.sub.3, C.sub.60, C.sub.70, PC.sub.61BM, PC.sub.71BM, or fullerene, or a functionalized material thereof, or SnO.sub.2 or functionalized SnO.sub.2 (e.g., functionalized with acetate)); and (e) a cathode (e.g., any suitable cathode, such as Fe, C, Ni, Pt, Ag, Al, or Cu). In other embodiments, the PSC is a flexible PSC.
[0087] Some embodiments of the invention include a PSC (e.g., as disclosed herein) comprising (a) an anode (e.g., any suitable anode such as ITO/glass or FTL/glass); (b) an electron transport layer (ETL) (e.g., any suitable ETL, such as SnO.sub.2, TiO.sub.2, or ZnO); (c) a perovskite layer (e.g., any suitable perovskite, such as one or more of CH.sub.3NH.sub.3PbX.sub.3, CH.sub.3NH.sub.3PbI.sub.3, H.sub.2NCHNH.sub.2PbX.sub.3, or CH.sub.3NH.sub.3SnX.sub.3, where X is a halogen (e.g., iodide, bromide or chloride) which can be the same or different between or within each formula; (d) a hole transport layer (HTL) (e.g., a material selected from an organic material, a metal oxide, NiO.sub.x, or CuO, or a functionalized material thereof, or NiO.sub.x or functionalized NiO.sub.x (e.g., functionalized with acetate)); and (e) a cathode (e.g., any suitable cathode, such as Fe, C, Ni, Pt, Ag, Al, or Cu). In other embodiments, the PSC is a flexible PSC.
[0088] Other embodiments of the invention include a PSC (e.g., as disclosed herein) comprising (a) an anode (e.g., any suitable anode such as ITO/glass or FTL/glass); (b) a hole transport layer (HTL) (e.g., any suitable HTL, such as NiO.sub.x, PTAA or PTAA/PFN); (c) a perovskite layer (e.g., any suitable perovskite, such as one or more of CH.sub.3NH.sub.3PbX.sub.3, CH.sub.3NH.sub.3PbI.sub.3, H.sub.2NCHNH.sub.2PbX.sub.3, or CH.sub.3NH.sub.3SnX.sub.3, where X is a halogen (e.g., iodide, bromide or chloride) which can be the same or different between or within each formula; (d) an electron transport layer (ETL) (e.g., prepared as disclosed herein, such as in original claim 1 or in any of the methods disclosed herein); and (e) a cathode (e.g., any suitable cathode, such as Fe, C, Ni, Pt, Ag, Al, or Cu). In other embodiments, the PSC is a flexible PSC.
[0089] Some embodiments of the invention include a PSC (e.g., as disclosed herein) comprising (a) an anode (e.g., any suitable anode such as ITO/glass or FTL/glass); (b) an electron transport layer (ETL) (e.g., any suitable ETL, such as SnO.sub.2, TiO.sub.2, or ZnO); (c) a perovskite layer (e.g., any suitable perovskite, such as one or more of CH.sub.3NH.sub.3PbX.sub.3, CH.sub.3NH.sub.3PbI.sub.3, H.sub.2NCHNH.sub.2PbX.sub.3, or CH.sub.3NH.sub.3SnX.sub.3, where X is a halogen (e.g., iodide, bromide or chloride) which can be the same or different between or within each formula; (d) a hole transport layer (HTL) (e.g., prepared as disclosed herein, such as in original claim 1 or in any of the methods disclosed herein); and (e) a cathode (e.g., any suitable cathode, such as Fe, C, Ni, Pt, Ag, Al, or Cu). In other embodiments, the PSC is a flexible PSC.
[0090] The presently-disclosed subject matter is further illustrated by the following specific but non-limiting examples. The following examples may include compilations of data that are representative of data gathered at various times during the course of development and experimentation related to the present invention.
EXAMPLES
Example Set ADirect Deposition of Non-Aqueous SnO.SUB.2 .Dispersion by Blade Coating on Perovskite for the Scalable Fabrication of Perovskite Solar Cells
[0091] The device architecture of a perovskite solar cells (PSC) sometimes involves a perovskite absorber sandwiched between n-type and p-type semiconductors in either a planar n-i-p or an inverted p-i-n structure. The n-type semiconductor plays a role as the electron transport layer (ETL) in the extraction of the photogenerated electrons from the active perovskite material, the electron transportation to the electrode, and the blocking of hole transport during the conversion of light into electricity. Therefore, it can be desirable for ETL materials to have a suitable bandgap and proper energy alignment with the perovskite along with high electron mobility and conductivity.
[0092] The direct deposition of fully solution-processed SnO.sub.2 onto a perovskite absorber layer in a p-i-n structure has not yet been reported. The absence of solution-processed SnO.sub.2 ETLs in p-i-n structures can, in part, be attributed to solvent incompatibility between the SnO.sub.2 and perovskite. The library of the perovskite compatible solvents is limited and excludes highly polar solvents that are typically used to prepare SnO.sub.2 dispersions. This is further complicated when using scale-up coating techniques, such as blade coating, where the evaporation kinetics result in prolonged exposure of the perovskite to solvent. Dispersions of metal oxides that are more amenable to blade coating onto a perovskite should therefore be prepared using nonpolar or less-polar organic solvents.
[0093] In this example, we report the direct deposition of a SnO.sub.2 thin film as an ETL on perovskite in p-i-n device structure by blade coating under ambient conditions. To enable the direct deposition of SnO.sub.2 on the perovskite, SnO.sub.2 nanoparticles synthesized using the sol-gel method were functionalized with acetic acid to obtain particles of tin oxide acetate (SnO.sub.2-A). The functionalization of SnO.sub.2 with acetate enables the formation of a stable colloidal dispersion of SnO.sub.2-A in the anhydrous ethanol, which was directly deposited on the perovskite film. The SnO.sub.2 based device exhibited an average PCE of 12.27% with a champion PCE of 14.1%. The devices maintained 95.8% of the average initial PCE after 40 days.
Results and Discussion
[0094] A perovskite compatible SnO.sub.2 ink was prepared by functionalization of SnO.sub.2 nanoparticles to enhance dispersibility in non-aqueous solvents (
[0095] In contrast to hydrous-SnO.sub.2, the SnO.sub.2-A nanoparticles are readily dispersed in protic organic solvents such as ethanol and isopropanol. Without being bound by theory, the enhanced dispersibility of the SnO.sub.2-A particles in protic organic solvents could be attributed to the formation of a hydrogen bonding network between the surface bonded acetate, excess acetic acid, and ethanol. In some instances, longer chain carboxylates could more effectively prevent agglomeration of the SnO.sub.2 nanoparticles and enable the formation of a stable colloidal dispersion of SnO.sub.2 in perovskite compatible non-polar organic solvents; in other instances, residual longer chain ligand in the ETL could hamper the charge transfer process and reduce the overall efficiency of the PSCs.
[0096] We selected to functionalize SnO.sub.2 with a short-chain carboxylic acid even though this limits our selection of solvents for the ink formulation to anhydrous ethanol. To study the perovskite compatibility with the dispersion medium, a dispersion of SnO.sub.2-A in anhydrous ethanol was deposited directly on the top of the perovskite layer of CH.sub.3NH.sub.3PbI.sub.3 (MA=methylammonium) via blade coating. The XRD patterns of perovskite before and after deposition of SnO.sub.2 on the perovskite are shown in
[0097] The dynamics of the charge carrier activity of the solution phase deposited SnO.sub.2 layer on perovskite were studied employing photoluminescence (PL) and time-resolved PL (TRPL) spectroscopy. The steady-state PL spectra of the perovskite and perovskite/SnO.sub.2 on a glass substrate are shown in
[0098] Based on the encouraging XRD, PL, and TRPL results, we fabricated PSCs with a p-i-n architecture employing SnO.sub.2-A as the ETL. A series of planar PSCs were fabricated on indium tin oxide (ITO) coated glass with a polytriarylamine (PTAA) hole transport layer (HTL) and a poly[(9,9-bis(3-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) interfacial layer. The overall device architecture is ITO/PTAA/PFN/CH.sub.3NH.sub.3PbI.sub.3/SnO.sub.2-A/Ag. A schematic representation of device architecture is showing in
[0099] The deposition of SnO.sub.2-A on the fully converted perovskite yields a uniform layer with a reflective surface.
[0100] The J-V characteristics of the fabricated cells were measured under one sun condition (AM 1.5G, 100 mW/cm.sup.2) and their corresponding photovoltaic parameters including power conversion efficiency (PCE), fill factor (FF), short-circuit current density (J.sub.sc), and open-circuit voltage (V.sub.oc) were recorded. The champion device exhibited a PCE of 14.1% with a J.sub.sc of 22.61 mA/cm.sup.2, a V.sub.oc of 1.023 V, and a FF of 61% (
[0101] To understand the stability of the fabricated device, sample devices were stored in a nitrogen flow box after initial J-V measurements were recorded. The devices were stored without any encapsulation and the J-V characteristics were re-evaluated after 40 days.
Conclusions
[0102] In summary, the solution phase deposition of a non-aqueous dispersion of SnO.sub.2 nanoparticles directly onto a CH.sub.3NH.sub.3PbI.sub.3 perovskite by a blade coating technique was demonstrated on a p-i-n device architecture. The acetate functionalized nanoparticles, SnO.sub.2-A, were synthesized using an aqueous reaction pathway that allowed for the formulation of a stable dispersion in a anhydrous ethanol. There was no observation of a PbI.sub.2 peak in the XRD spectrum after the deposition of the ink on CH.sub.3NH.sub.3PbI.sub.3 indicating that there is no observable damage to the perovskite thin film. The photoluminescence results demonstrated that the electrons are being transported from the perovskite layer and the cross-sectional SEM show a smooth interface between the CH.sub.3NH.sub.3PbI.sub.3 and SnO.sub.2 films. The champion PSCs exhibited a PCE of 14.1% with an active area of 0.25 cm.sup.2 and maintained 95.8% of this after 40 days.
Experimental Section
Synthesis of Hydrous-SnO.SUB.2
[0103] The tin oxide nanoparticles were prepared using sol-gel methods by neutralizing aqueous tin chloride solution with sodium hydroxide (McManus et al., Highly soluble ligand stabilized tin oxide nanocrystals: gel formation and thin film production. Cryst. Growth Des. 2014, 14, 4819-4826). In general, a 0.5 M aqueous solution of SnCl.sub.4 was prepared by dropwise addition of anhydrous SnCl.sub.4 to deionized (DI) water. To the vigorously stirred aqueous solution of SnCl.sub.4, freshly prepared 5M NaOH solution in DI water was added dropwise until the pH reached pH 6.5. The resulting white precipitate of hydrous-SnO.sub.2 was aged for 12 hours, collected by centrifugation, and washed repeatedly by dispersion in DI water/centrifugation until the aqueous layer was chloride free. The washed hydrous-SnO.sub.2 tin oxide particles were dried at room temperature for 24 hours. The formation of SnO.sub.2 was confirmed by XRD analysis. The actual mass of SnO.sub.2 present on the hydrous SnO.sub.2 was calculated to be 70% from TGA analysis.
Synthesis of SnO.SUB.2.-A and Ink Formulation
[0104] The acetate functionalized nanoparticles, SnO.sub.2-A, were prepared based on the literature procedure (McManus et al., Highly soluble ligand stabilized tin oxide nanocrystals: gel formation and thin film production. Cryst. Growth Des. 2014, 14, 4819-4826). In general, hydrous-SnO.sub.2 and glacial acetic acids were mixed in a 1:1mass:volume ratio. In a typical preparation, 4 grams of hydrous-SnO.sub.2 were mixed with 4 mL of glacial acetic acid. The mixture was then heated at reflux for one hour in a closed container. The mixture initially formed a milky white colloidal dispersion that became colorless and transparent upon formation of SnO.sub.2-A. If the reaction mixture does not become completely colorless and transparent, the undissolved hydrous-SnO.sub.2 can be removed via centrifugation. The percentage of SnO.sub.2 in the solution was determined from TGA analysis. An aliquot of the SnO.sub.2-A solution was dispersed in anhydrous ethanol to make an ink that contains 2% (m/v) SnO.sub.2 suitable for deposition on directly on perovskite by blade coating. For XRD and FT-IR analysis, the initial SnO.sub.2-A solution was transferred to an evaporating dish and the solvent was evaporate overnight. The solid product was dried in a vacuum oven at 100 C. for 2 hours prior to analysis.
Device Fabrication
[0105] A pre-ITO-coated glass substrate was cut into 1 in.2 in. pieces and they were cleaned using Liquinox detergent solution, acetone, isopropanol, and a nitrogen flush. The cleaned glass substrates were treated with UV-Ozone for 15 mins immediately before the sequential deposition of PTAA, PFN, CH.sub.3NH.sub.3PbI.sub.3, and SnO.sub.2-A by blade coating in an ambient environment. A PTAA solution was prepared by dissolving 8 mg of PTAA in 1 ml of toluene. A 12 L aliquot of the PTAA solution was used for blade coating with a blade gap of 100 m at a coating speed of 10 mm/sec, followed by heating at 100 C. for 10 mins and then cooled down to room temperature. Next, 12 L of a 0.4 mg/mL PFN solution in methanol was blade coated on the PTAA layer at a coating speed of 7.5 mm/sec with a blade gap of 100 m. The perovskite precursor solution was prepared by dissolving methylammonnium iodide and PbI.sub.2 in a mixture DMF:DMSO:NMP with a volume ratio of 0.91:0.07:0.02 to get a 1.2 M solution (Ouyang et al., Toward scalable perovskite solar modules using blade coating and rapid thermal processing. ACS Appl. Energy Mater. 2020, 3, 3714-3720). A 20 L aliquot of the perovskite precursor solution was deposited by blade coating with a blade gap of 150 m and at a coating speed of 7.5 mm/sec. Immediately after the deposition of perovskite precursor solution, the wet film was pre-dried using an N.sub.2 air knife followed by hotplate annealing at 140 C. for 2 mins. Finally, 20 L of the SnO.sub.2-A dispersion in anhydrous ethanol was deposited on the perovskite with a blade gap height of 100 m and at the coating speed of 7.5 mm/sec, followed by annealed at 100 C. for 10 min. The fabrication of PSCs having a device architecture of glass-ITO/PTAA/PFN/CH.sub.3NH.sub.3PbI.sub.3/SnO.sub.2-A/Ag was completed by depositing 100 nm of silver on the SnO.sub.2-A ETL employing thermal evaporation. After silver deposition, devices were mechanically scribed into an active area of 0.25 cm.sup.2.
Physical Methods
[0106] Powder x-ray diffraction (PXRD) patterns were measured using a Bruker D8 Discover X-ray diffractometer. Infrared spectra were collected using a Thermo Nicolet Avatar 360 FT-IR with Smart iTR. The cross-sectional SEM images were recorded using a JEOL 7000field-emission scanning electron microscope (SEM). PL analysis was carried out using a Renishaw in Via Raman microscope with a CCD detector and a 632 nm HeNe laser source. The current density-voltage (J-V) characteristics of devices were measured using a Class AAA solar simulator having a Xenon arc lamp with one sun condition (AM1.5G, 100 mW/cm.sup.2). Prior to the device measurements, the solar simulator was calibrated using a NREL-certified Si reference cell. Devices were tested from 1.2 to 0 V at a scan rate of 100 mV/s with step size of 10 mV.
Example Set BSolvation of NiO.SUB.x .for Hole Transport Layer Deposition in Perovskite Solar Cells (PSC)
[0107] A series of nickel oxide (NiO.sub.x) inks, in the perovskite antisolvent chlorobenzene (CB) containing 15% ethanol, were prepared for the fabrication of p-i-n perovskite solar cells by blade coating. The inks included triethylamine (Et.sub.3N) and alkyl xanthate salts as ligands to disperse NiO.sub.x particle aggregates and stabilize suspension. A total of four inks were evaluated: 0X (Et.sub.3N with no alkyl xanthate), 4X (Et.sub.3N+potassium n-butyl xanthate), 12X (Et.sub.3N+potassium n-dodecyl xanthate), and 18X (Et.sub.3N+potassium n-octadecyl xanthate). The inks were characterized by UV-visible spectroscopy and FT-IR spectroscopy and the resulting films analyzed by thermogravimetry and scanning electron microscopy. Devices prepared using the 0X ink resulted in a peak power conversion efficiency (PCE) of 14.47% (0.25 cm.sup.2) and 9.96% (1 cm.sup.2). The 0X devices showed no significant loss of PCE after 100 days in a nitrogen flow box. Devices prepared with inks containing alkyl xanthate ligand had lower PCE that decreased with decreasing chain length, 18X>12X>4X.
[0108] In this example, we report the development of soluble NiO.sub.x particles for the solution phase deposition of inorganic HTLs for use in scalable PSCs. Some PSC devices include a perovskite active layer between an electron transport layer (ETL) and a hole transport layer (HTL) on an indium tin oxide (ITO) or fluorine-doped tin oxide (FTO) substrate with a metal (Ag or Au) top electrode. The architecture of the device can be n-i-p or p-i-n depending on the relative ordering of the ETL (n), perovskite (i), and HTL (p). The HTL and ETL layers can have roles in improving the photovoltaic performance of PSCs through modulation of charge carrier recombination and charge extraction capabilities.
[0109] In some aspects of this example, the development of chlorobenzene (CB) compatible NiO.sub.x nanoparticles is explored using ligands with variable alkyl chain lengths in order to obtain NiO.sub.x films with a reduced presence of residual organic ligands. A series of inks with alkyl xanthates (ROCS.sub.2.sup.) with various chain lengths and triethylamine (Et.sub.3N) have been prepared (
Experimental Section
Materials and Methods
[0110] The NiO.sub.x particles were synthesized by known solvothermal methods (Beach et al, Chem. Phys. 2009, 115, 371-377). Briefly, nickel acetylacetonate (Ni(acac).sub.2) was dissolved in methyl ethyl ketone (MEK) to form a 0.1 M solution. The resulting solution was sparged with N.sub.2 gas for 30 minutes and then sealed in a Teflon lined Parr reactor. The reactor was heated at 225 C. for 16-18 hours. The reactor was cooled to room temperature and the resulting product isolated from the solution by centrifugation for 15 minutes. The crude NiO.sub.x product was cleaned by repeated suspension/isolation with MEK and isopropanol (IPA). The potassium xanthates salts were prepared from potassium hydroxide, carbon disulfide, and the appropriate alcohol using reported methods. Xanthates with 4- and 12-carbon chains were isolated as yellow solids as described by Carta (Carta et al., J. Med. Chem. 2013, 56, 4691-4700). The 18-carbon chain xanthates was prepared as reported by Sawant as white solids (Sawant et al., Langmuir 2001, 17, 2913-2917). The sodium carbonate salts were prepared as flaky, white solids from sodium phenoxide, carbon dioxide, and the appropriate alcohol according to the method reported by Ichiro (Ichiro et al., B. Chem. Soc. Jpn. 1976, 49, 2775-2779).
Physical Methods
[0111] Powder x-ray diffraction (PXRD) patterns of NiO.sub.x powders were measured using Bruker Discovery D8 High resolution X-ray diffractometer with Cu K radiation (1.54 , 40 KV, at a step speed of 0.7 sec/step, 25-85). Films were deposited using an air knife equipped Zehntner ZAA 2300 Automatic film applicator and ZUA 2000 Universal Applicator. The surface morphology of NiO.sub.x powder and films were characterized using a top-view scanning electron microscope (SEM, Thermo-Fisher Scientific Apreo C LoVac FESEM). Film thickness and roughness were measured using a Veeco Dektak 8M Profilometer. Absorption spectra NiO.sub.x were measured using a UV-visible spectrophotometer (Agilent 8453). The stability and particle size of NiO.sub.x inks were characterized by performing Zeta potential measurements (Brookhaven Instrument Corporation 90Plus Particle Size Analyzer). Infrared spectra of organics and inks were collected using a Thermo Nicolet Avatar 360 FT-IR with Smart iTR. Thermal decomposition of xanthates and associated inks was identified by thermogravimetric analysis (TGA, Differential Scanning Calorimeter Q20 30 C.-800 C., 20 C./min). The current density-voltage (J-V) characteristics of devices were measured using a Class AAA solar simulator having a Xenon arc lamp with one sun condition (AM1.5G, 100 mW/cm.sup.2). Prior to the device measurements, the solar simulator was calibrated using a NREL-certified Si reference cell. Devices were tested from 1.2 to 0 V at a scan rate of 100 mV/s with step size of 10 mV.
Device Fabrication
[0112] Devices with the following p-i-n architecture were fabricated: glass/ITO/NiO.sub.x/PFN/MAPbI.sub.3/C.sub.60/BCP/Ag where PFN and BCP are poly[(9,9-bis(3-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] and bathocuproine, respectively. The ITO coated glass was cut into 12 substrates that were cleaned by N.sub.2 flush, followed by UV-O.sub.3 treatment for 15 minutes and a second N.sub.2 flush. No further steps were taken to clean the ITO substrates. The cleaned ITO substrates were immediately used for sequential deposition of NiO.sub.x, PFN, and MAPbI.sub.3 by blade coating. The NiO.sub.x inks were prepared by sonication of NiO.sub.x particles (20 mg) in 200 L of a 3:1 (v/v) Et.sub.3N/EtOH mixture for 60 minutes at 65 C. in a closed vial. The resulting suspension was diluted with 700 L CB and 100 L EtOH to make a 20 mg/mL NiO.sub.x solution. For NiO.sub.x inks containing xanthate ligands, 0.125 eq. of ligand was added to the CB in the dilution step. After dilution, the suspensions were sonicated with heating at 65 C. During this step, inks containing xanthate ligands underwent a color change as shown in
[0113] Initial n-i-p devices with a glass/ITO/SnO.sub.2/MAPbI.sub.3/NiO.sub.x/Ag architecture were constructed using 20 L inch.sup.2 of 3% (wt %) commercial SnO.sub.2 nanoparticles as the ETL. Optimized SnO.sub.2 films were deposited using blade coating with a blade gap of 100 m blade gap at 5 mm sec.sup.1 on a 100 C. heated stage followed by annealing at 150 C. for 1 hour. All other layers were deposited in the same manner as described above.
Results and Discussion
Ink Formulation and Characterization
[0114] A series of NiO.sub.x nanoparticles have been prepared that can be suspended in chlorobenzene (CB) as inks for the preparation of hole transport layers with perovskite photovoltaics. The NiO.sub.x particles were initially ligated with the Lewis base triethylamine (Et.sub.3N) to which alkyl xanthate (ROCS.sub.2.sup.) ligands were added (
[0115] The initial NiO.sub.x particles were prepared by solvothermal synthesis as described by Beach (Beach et al., Mater. Chem. Phys. 2009, 115, 371-377). The identity and purity of the synthesized nanoparticles was confirmed by powder x-ray diffraction (PXRD) studies, which showed the expected peaks at 36.8 (111), 42.8 (200), 62.3 (220), 74.7 (311), 78.8 (222). From the PXRD, the crystal size was estimated to be approximately 8 nm based on the Scherrer equation. These small particles tend to agglomerate and form large aggregates in the solid phase as shown in the SEM image in
[0116] To quantify the effect of Et.sub.3N on the dispersion stability of the NiO.sub.x particles, the -potential was measured for the 0X solution. The -potential measures the potential difference between the dispersed particle and the medium with stable suspensions generally having values of at 30 mV. The -potential can be dependent on the composition of the particles and their chemical environment. Prior to the addition of Et.sub.3N, the -potential of the initially prepared NiO.sub.x particles was 6.193.0 mV consistent with their observed agglomeration. Addition of 15% Et.sub.3N to yield the 0X particles increased the -potential to 27.293.9 mV. The results indicate that Et.sub.3N, even in the absence of additional alkyl xanthate ligands, is sufficient to stabilize the suspension of NiO.sub.x in CB.
[0117] Addition of alkyl xanthate to the 0X ink results in a ligand exchange process with coordination of xanthate to the NiO.sub.x particles, as observed by UV-Visible spectroscopy. The 0X ink has a primary excitonic peak centered at 300 nm and the ink is visually a light tan in CB. Addition of alkyl xanthates to the NiO.sub.x particles yields dark brown suspensions after heating and filtration (
[0118] The coordination of the alkyl xanthate ligands to the NiO.sub.x particles was further confirmed by FT-IR spectroscopy. The spectrum of the 12X alkyl xanthate shows a CS stretch at 1070 cm.sup.1 that shifts to 1030 cm.sup.1 in the ink and a COC stretch at 1120 cm.sup.1 to 1230 cm.sup.1 upon addition of the NiO.sub.x (See
[0119] Thermal gravimetric analysis (TGA) was performed on the alkyl xanthate ligands and their corresponding inks to determine their stability under annealing conditions. Since residual long-chain compounds in the NiO.sub.x layer have been shown to lower the PCE of PSCs, ligands that decompose during annealing may offer an advantage. Prior TGA studies on synthesized NiO.sub.x particles without additional ligands yielded an annealing temperature of 300 C. (Beach et al., Mater. Chem. Phys. 2009, 115, 371-377). The TGA of the 12X salt, as a powder, shows an initial, small mass loss due to dehydration followed by a sharp, substantial mass loss associated with xanthate decomposition from 210 to 315 C. (
Film Deposition
[0120] The 0X-18X inks were deposited as thin films on ITO glass by blade coating with a blade gap of 225 m at a speed of 5 mm sec.sup.1. The films were annealed at 300 C. for 20 minutes. Using these parameters, film thicknesses of approximately 40 nm, as determined with a Dektak surface profilometer, were reproducibly obtained. The roughness of the 0X film is measured to be 5.9 nm by Dektak. SEM imaging of the 0X film shows a tightly packed film with no visible pinholes (
[0121] For inks containing xanthate ligands, the film quality is dependent on the length of the carbon chain. The SEM image of the 18X film shows uniform coverage with the presence of some pinholes (
Device Performance
[0122] To evaluate the effect of xanthate ligands on PSC performance, a series of devices having an architecture of glass/ITO/NiO.sub.x/PFN/MAPbI.sub.3/C.sub.60/BCP/Ag were constructed by blade coating of the NiO.sub.x, PFN, and MAPbI.sub.3 and thermal evaporation of C.sub.60, BCP, and Ag. Cells were mechanically scribed into an active area of 0.25 cm.sup.2 and tested under 1 sun condition. PFN was incorporated to improve the surface wetting of the perovskite deposition using known blade coating parameters.
TABLE-US-00001 TABLE B1 Photovoltaic parameters of champion devices Area PCE V.sub.oc J.sub.sc FF R.sub.s R.sub.sh Ink (cm.sup.2) (%) (mV) (mA/cm.sup.2) (%) ( cm.sup.2) 0X 0.25 14.47 1049.32 19.23 71.72 8.0 728.7 18X 0.25 7.61 891.80 16.22 52.61 6.9 316.6 12X 0.25 4.86 817.16 12.44 47.84 11.9 326.9 4X 0.25 0.19 89.99 8.64 25.03 10.3 11.2 0X 1.00 9.96 970.45 17.81 57.61 8.5 615.9 18X 1.00 7.51 968.89 13.95 55.58 8.4 573.9
[0123] The relative values of J.sub.sc are consistent with the differences in NiO.sub.x film quality observed in the SEM images, which can affect the quality of the perovskite layer. The J.sub.sc value is highest for 0X and decreases in films containing xanthate ligand as the chain length decrease. This is consistent with previous studies that show a decrease in J.sub.sc can occur with an increasing size and density of pinholes in the HTL; also noted in previous studies, V.sub.oc can be dependent on total surface coverage with a nearly constant value when there is at least 80% surface coverage. In the present study, the V.sub.oc decreases from 0X to 18X to 12X consistent with decreasing surface coverage within this series, followed by a substantial drop for 4X, which performed as a photo-resistor, due to its poor film quality. Overall, the high V.sub.oc and J.sub.sc of the 0X device indicate a high level of uniformity in the HTL and subsequently the perovskite depositions. Variations in the J.sub.sc being due to small variations in the perovskite itself but having no overall effect on the trends observed.
[0124] Further confirming the significant effects of the film quality, the FF shows a nearly 20% drop from the 0X to the 18X devices. The FF is dependent on the shunt (R.sub.sh) and series (R.sub.s) resistance of the device. The series resistance in these two films is similar (0X: 8.0 cm.sup.2 vs 18X: 6.9 cm.sup.2) despite the inclusion of a long chain xanthate ligand in the 18X ink. This is attributed to removal of the xanthate ligand during the annealing step. However, the shunt resistance of the 0X film is more than twice that of the 18X film (0X: 728 cm.sup.2 vs 18X: 316 cm.sup.2) resulting in the improved FF in the 0X device. The lower shunt resistance in the 18X device is consistent with the greater presence of pinholes noted above.
[0125] Next, 0X and 18X were evaluated as 1 cm.sup.2 devices to test their applicability for large scale production. The J-V curves are shown in
[0126] The long-term stability of a 0X and 18X device was evaluated following storage in a nitrogen flow box for 100 days exposed to lab lighting. Device performance is summarized in Table B2. The 18X device shows a general degradation in quality with decreases in J.sub.sc, R.sub.sh, and FF resulting in a drop in PCE after 100 days. The 0X device shows greater stability. There is a decrease in V.sub.oc and FF over 100 days, but there is also an unexpected increase in J.sub.sc and R.sub.sh resulting in no statistical change in PCE. Without being bound by theory, this increase could be due to the further removal of Et.sub.3N from the device interface; Et.sub.3N having a vapor pressure of 7.2 kPa at 20 C. would further evaporate with aging of the device. Without being bound by theory, the higher stability of the 0X device compared to the 18X device could be attributed to the quality of the NiO.sub.x film and the quality of the resulting perovskite to have less trap states that would lead to film degradation.
TABLE-US-00002 TABLE B2 Photovoltaic parameters for 0.25 cm.sup.2 devices before and after storage in nitrogen flow box for 100 days PCE V.sub.oc J.sub.sc FF R.sub.s R.sub.sh Ink (%) (mV) (mA/cm.sup.2) (%) ( cm.sup.2) 0X 10.00 988.01 14.41 70.25 3.3 990.7 Initial 0X 11.16 956.53 18.11 64.41 7.3 1306.5 100 day 18X 7.61 891.80 16.22 52.61 6.9 316.6 Initial 18X 5.06 884.13 14.13 40.57 6.4 103.0 100 day
[0127] Given the performance of p-i-n devices using of the 0X ink, construction of a n-i-p device was undertaken with a glass/ITO/SnO.sub.2/MAPbI.sub.3/NiO.sub.x/Ag architecture (
Conclusions
[0128] A series of ink formulations have been developed that successfully suspend NiO.sub.x nanoparticles in the perovskite antisolvent CB in mixtures containing EtOH with Et.sub.3N (0X) or Et.sub.3N/alkyl xanthates (4X, 12X, 18X). The carbon chain length of the alkyl xanthate was varied to probe its effect on ink performance. Although hydrophobic chelating ligands were previously used to solubilize NiO.sub.x for fabrication of PSCs, we found that Et.sub.3N alone was sufficient to stabilize NiO.sub.x nanoparticles in solution and disperse aggregates upon sonication. In fact, the 0X ink yielded the best film quality and device performance with champion PCEs of 14.47% (0.25 cm.sup.2) and 9.96% (1 cm.sup.2). The 0X cells were stable for 100 days in a nitrogen flow box with no significant change in PCE. For PSCs containing alkyl xanthate ligands, the best film quality and device performance was obtained for 18X. Without being bopund by theory, this could be attributed to preferential ordering of the NiO.sub.x on the surface due to dispersion interactions of the long carbon chain and the degradation of the alkyl xanthate during thermal annealing. However, the 18X inks led to more pinholes than the 0X ink resulting in a decrease in PCE. Shorter chain alkyl xanthates had lower performance with 4X inks failing to form films. Overall, our results provide a new formulation for the preparation of NiO.sub.x inks in the perovskite antisolvent CB based on the volatile and weakly coordinating Et.sub.3N ligand. This provides several advantages over non-volatile charged ligands with long carbon chains.
Example Set CNiO.SUB.x .and Cu Doped NiO.SUB.x .Nanoparticles
[0129] A 5 M solution of Ni(NO.sub.3).sub.2.Math.6H.sub.2O was prepared by dissolving Ni(NO.sub.3).sub.2.Math.6H.sub.2O in 25 mL of deionized water. While stirring vigorously a 10 M solution of NaOH was added by dropwise addition until the pH was adjusted to 10. The resulting precipitated Ni(OH).sub.2 was then collected by centrifuge and washed repeatedly with deionized water. After washing the Ni(OH).sub.2 was fully dried at 80 C. The dry Ni(OH).sub.2 was then collected and annealed at 270 C. for 15 min to convert to NiO.sub.x. Copper doped particles where prepared in the same manner with a 5 mol % Cu(NO.sub.3).sub.2.Math.3H.sub.2O substitution in the original Ni(NO.sub.3).sub.2.Math.6H.sub.2O solution.
[0130] Powder x-ray diffraction confirms retention of the cubic NiO.sub.x structure upon addition of copper (
[0131] Doped and undoped nanoparticles where suspended in a 2:1 H.sub.2O:Isopropyl alcohol solution by brief sonication and then filtered by centrifugation for 2 hr followed by filtering through a 0.2 m nylon filter. The resulting suspensions were found to be stable up to 3 days by dynamic light scattering (
TABLE-US-00003 TABLE C1 Cell Performance parameters and IPL conditions Sample PCE (%) J.sub.sc (mA/cm.sup.2) V.sub.oc (V) FF (%) NiO.sub.x 8.85 20.49 1.01 42.5 Average NiO.sub.x 8.06 20.29 0.99 39.8 Ni.sub.0.94Cu.sub..06O.sub.x 11.16 20.37 0.95 57.6 Average Ni.sub.0.94Cu.sub..06O.sub.x 9.86 19.82 0.90 54.7 Energy Voltage Duration Delay IPL Parameters (kJ) (V) (s) (ms) Pulses NiO.sub.x 1.22 1940 1000 200 5 MAPbI.sub.3 0.37 1500 600 1000 10
Example Set DYttrium Doped SnO.SUB.2 .as an Efficient Blocking Layer for Inverted Flexible Perovskite Solar Cells (f-PSCs)
[0132] In this example, we investigated the direct deposition of tin (IV) oxide as an electron transport layer on the top of perovskite for the high-performance f-PSCs. We synthesized SnO.sub.2 nanoparticles using the sol-gel method and functionalized them with acetate through ligand exchange allowing their dispersion in anhydrous ethanol. Additionally, we investigated in situ yttrium doping of SnO.sub.2 during synthesis to enhance the performance of SnO.sub.2 as an ETL. Nonaqueous dispersions of pristine and yttrium doped SnO.sub.2 were directly deposited on the perovskite by blade coating followed by air knife treatment. There was no detectable damage to the underlying perovskite layer as evidenced by x-ray diffraction and scanning electron microscopy. Photoluminescence spectroscopy and device performance statistics confirm more electron extraction by yttrium doped SnO.sub.2 as compared to pristine SnO.sub.2. After, yttrium doping, the champion power conversion efficiency was increased above 18% from 14.40%, which is unprecedented for an inverted device in flexible ITO-PET substrate employing SnO.sub.2 as an ETL. This example indicates scalable deposition of fully solution-processed metal oxide charge transfer layers directly on the perovskite should achieve highly efficient large-area flexible perovskite solar cells.
[0133] The perovskite solar cells (PSCs) device architecture can sometimes include a perovskite thin layer sandwiched between two charge transport layers and can be categorized as n-i-p or p-i-n, where n represents an electron transport layer (ETL) and p represents a hole transport layer (HTL). The ETL can play a role in PSCs including extraction and transportation of photogenerated electrons and preventing electron-hole recombination as a hole blocking layer. Therefore, ETL materials sometimes have a suitable band gap and proper energy alignment with the perovskite, along with high electron mobility and conductivity.
[0134] In this example, we synthesized Yttrium doped SnO.sub.2 nanoparticles (Y:SnO.sub.2) by sol-gel method, in part, to improve the electronic properties of the low temperature processed SnO.sub.2. The Y:SnO.sub.2 nanoparticles were functionalized with acetic acid to obtain acetate functionalized Y:SnO.sub.2 (Y:SnO.sub.2-A). The functionalization of Y:SnO.sub.2 with acetate enables the formation of a stable colloidal dispersion of Y:SnO.sub.2-A in anhydrous ethanol, which was directly deposited on the perovskite film by blade coating. The Y doping modifies the electronic properties of the ETL leading to an efficient extraction and transportation of the charge from underneath perovskite layer. As compared to pristine SnO.sub.2, the champion power conversion efficiency (PCE) of the Y:SnO.sub.2 device on the flexible PET substrate has increased from 14.40% to 18.2%. The work includes an analysis of the Y doping, thin film, and device characterization. This example shows that the scale-up of PSCs using inexpensive inorganic ETLs by high-throughput processes are possible.
Result and Discussion
[0135] Pristine tin (IV) oxide (SnO.sub.2) and yttrium doped tin (IV) oxide (Y:SnO.sub.2) nanoparticles were synthesized using a solgel process as previously described (Chapagain et al. (2021) Direct Deposition of Nonaqueous SnO.sub.2 Dispersion by Blade Coating on Perovskites for the Scalable Fabrication of p-i-n Perovskite Solar Cells ACS Appl. Energy Mater., Vol. 4, No. 10, pp. 10477-10483); however, yttrium doping was accomplished in situ by adding yttrium chloride to the to the precursor of SnO.sub.2 (that is, anhydrous SnCl.sub.4) during the synthesis process. Energy Dispersive X-ray Spectrometry (EDS) spectra of Y: SnO.sub.2 reveal the presence of a Y in SnO.sub.2 along with Sn and O (
[0136] The XRD peaks present at 26.4, 33.75, 51.86, and 64.37 are assigned to the (110), (101), (211), and (301) planes of the tetragonal rutile crystal structure of SnO.sub.2 and Y:SnO2. The XRD diffraction patterns of Y:SnO.sub.2 do not show any extra peak of impurities which implies that either the amount of yttrium is not enough to change crystal structure or to exist as a separate phase.
[0137] The elemental composition of the SnO.sub.2 and Y:SnO.sub.2 thin films were evaluated by X-ray photoelectron spectroscopy (XPS). Survey spectrum of Y:SnO.sub.2 indicates the presence of C1s, O1s, and Sn 3d peaks along with other associated peaks (
[0138] The deposition of SnO.sub.2 and Y:SnO.sub.2 nanoparticles directly on perovskite thin films can be accomplished by dispersion of the nanoparticles into perovskite compatible organic solvents. In Example A above, we functionalized SnO.sub.2 with an acetate ligand to produce functionalized SnO.sub.2 (SnO.sub.2-A) which is dispersible in anhydrous ethanol. Here, we adopted the same strategy for functionalization of the Y:SnO.sub.2 nanoparticles with an acetate yielding Y:SnO.sub.2-A. The functionalization of Y:SnO.sub.2 with acetate converts white amorphous tin oxide powder to a clear and colorless solution of functionalized tin oxide (Y:SnO.sub.2-A). The X-ray diffraction (XRD) patterns of Y:SnO.sub.2 before and after functionalization (data not shown) have similar peaks at 26.4, 33.75, 51.86, and 64.37 that are assigned to the (110), (101), (211), and (301) planes of the tetragonal rutile crystal structure of Y:SnO.sub.2. XRD analysis shows that there is no change in the crystal structure of Y:SnO.sub.2 after functionalization. The FTIR spectrum of SnO.sub.2 before functionalization shows a broad band at 3300 cm.sup.1 and a sharp band at 1640 cm.sup.1 associated with OH stretching and bending of adsorbed water at the surface of Y:SnO.sub.2. The OH stretching band is reduced in the FTIR spectrum of Y:SnO.sub.2-A, which indicates that the hydroxyl groups on the surface of Y:SnO.sub.2 have been replaced by acetate ligands; the coordination of acetate in Y:SnO.sub.2-A is confirmed by the presence of bands at 1715 and 1380 cm.sup.1 associated with CO stretching and scissoring vibrations of the acetate ligand. Additionally, FT-IR spectra of Y:SnO.sub.2 and Y:SnO.sub.2-A show a common feature at 650 cm.sup.1 which is associated with SnO stretching. Hence, the functionalization processes of SnO.sub.2 and Y:SnO.sub.2 are purely ligand exchange processes as evident by XRD and FT-IR analysis.
[0139] The overall scheme of the functionalization of Y:SnO.sub.2 nanoparticles with acetate to obtain Y:SnO.sub.2-A and ink formulation from Y:SnO.sub.2 in anhydrous ethanol is presented in
[0140] The dispersion of Y:SnO.sub.2-A nanoparticles can be deposited directly on the top of the perovskite layer via blade coating. After deposition, excess solvent can be removed quickly using a dry air knife. Here, annealing for 2 to 3 minutes at 100 C. ensures that the solvent is completely removed. See
[0141]
[0142] The XRD patterns of the perovskite before and after deposition of Y:SnO.sub.2-A dispersion in anhydrous ethanol on the perovskite (
[0143] Steady-state photoluminescence (PL) measurements were carried out to understand charge carrier dynamics between the perovskite active layer and SnO.sub.2-A and Y:SnO.sub.2-A (
[0144] To analyze the effect of Yttrium concentration in Y:SnO.sub.2-A on the photovoltaic performance of the PSCs, a series of planar PSCs were fabricated on a flexible PET/ITO-based substrate (f-PSCs) employing diluted SnO.sub.2-A and Y:SnO.sub.2-A as ETLs. The overall device structures were ITO/PTAA/PFN/CH.sub.3NH.sub.3PbI.sub.3/SnO.sub.2-A/BCP/Ag and ITO/PTAA/PFN/CH.sub.3NH.sub.3PbI.sub.3/Y:SnO.sub.2-A/BCP/Ag, where a polytriarylamine (PTAA) is used as a hole transport layer (HTL) and a poly[(9,9-bis(3-(N,N-dimethylamino) propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) as an interfacial layer. Here, PTAA, PFN, perovskite, and SnO.sub.2 layers were deposited by one-step blade coating methods whereas BCP and silver were deposited by thermal evaporation. Those fabricated f-PSCs were measured under AM 1.5 simulated sunlight. Before measurement, the solar simulator was calibrated using NREL certified silicon reference photodiode using a KG5 filter.
[0145] Device performance statistics of the f-PSCs vs doping concentrations of yttrium are presented in
TABLE-US-00004 TABLE D1 Summary of the average photovoltaic performance statistics of the f-PSCs with 0, 1, 2, and 3 mol % of Yttrium in SnO.sub.2 ETL with an active area of 0.1 cm.sup.2 Mol. % of Y Voc (V) Jsc (mA/cm.sup.2) FF (%) PCE (%) 0 1.01 0.03 22.18 0.80 57.83 2.5 13.0 0.77 1 1.02 0.02 22.83 0.77 60.83 5.0 14.22 1.11 2 1.07 0.01 22.62 0.68 64.17 3.2 15.56 1.05 3 1.00 0.02 22.38 0.67 64.71 4.5 14.52 1.12
[0146] An image of blade-coated f-PSCs are presented in
Conclusion
[0147] We synthesized yttrium doped tin (IV) oxide (Y:SnO.sub.2) via in situ addition of yttrium chloride to the solgel synthesis of SnO.sub.2. Both pristine SnO.sub.2 and Y:SnO.sub.2 nanoparticles were functionalized with acetate and diluted with anhydrous ethanol yielding a nonaqueous dispersion of SnO.sub.2-A and Y:SnO.sub.2-A. The non-aqueous dispersion of SnO.sub.2-A and Y:SnO.sub.2-A did not induce any observable damage to the perovskite during deposition by blade coating as evident by XRD and UV-Vis. The PL analysis shows Y:SnO.sub.2-A has better charge carrier dynamics than that of the pristine SnO.sub.2-A. We successfully fabricated inverted f-PSCs on the PET substrate by direct deposition of fully solution-processed SnO.sub.2-A and Y:SnO.sub.2-A on the perovskite by a scalable blade coating method. The f-PSCS with Y:SnO.sub.2-A as an ETL exhibit improved performance as compared to pristine SnO.sub.2-A. The optimum yttrium concentration was found to be 2 mol % yielding a 20% improvement in average performance, with increases to both the V.sub.oc and FF. The low temperature synthesized Y:SnO.sub.2-A is a promising ETL and blocking layer and is fully solution-processed. This material possesses multiple cost, scalability, and manufacturing advantages over traditional organic ETLs that could improve the competitiveness of commercial perovskite solar modules.
Experimental Section
Synthesis of SnO.sub.2 and Y:SnO.sub.2
[0148] Both SnO.sub.2 and Y:SnO.sub.2 nanoparticles were synthesized by a sol-gel method by neutralizing 1M aqueous tin (IV) chloride solution with 5M sodium hydroxide solution. The SnO.sub.2 and Y:SnO.sub.2 nanoparticles were synthesized similarly, but the Yttrium doping was accomplished in situ by adding Yttrium precursor to the precursor of tin oxide during the synthesis process. 1M aqueous tin (IV) chloride solution was prepared by dropwise addition of anhydrous tin (IV) chloride to deionized (DI) water. To the continuously stirred aqueous tin (IV) chloride solution, a freshly prepared aqueous solution of 5M sodium hydroxide was added dropwise until the pH reached 6.5. The resulting white precipitate of SnO.sub.2 was aged for 12 hrs, collected by centrifugation, washed repeatedly by dispersion in DI water, and in the mixture of 1:1 DI water and ethanol by centrifugation until the aqueous layer was free from chloride. The washed SnO.sub.2 nanoparticles were dried at room temperature. To prepare 1, 2, and 3 mol. % yttrium doped SnO.sub.2, a calculated amount of yttrium (III) chloride hydrate was added to the aqueous 1M tin (IV) chloride solution respectively.
Functionalization of SnO.sub.2 and Y:SnO.sub.2 with Acetate
[0149] Both SnO.sub.2 and Y:SnO.sub.2 were functionalized with an acetate based on Examples discussed herein. Here, SnO.sub.2 or Y:SnO.sub.2 was mixed with glacial acetic acid in a 1:1 mass by volume ratio. Then, the mixture of SnO.sub.2 and glacial acetic acid or Y:SnO.sub.2 and acetic acid were heated at reflux for 1 hr in a closed container fitted with a condenser and thermometer. The mixture initially forms milky white colloidal dispersion which becomes transparent upon the completion of functionalization. The presence of undissolved SnO.sub.2 nanoparticles leaves milky white coloration which can be removed via centrifugation. The percentage of SnO.sub.2 in the clear solution of functionalized SnO.sub.2 was determined from TGA analysis and the functionalized SnO2 nanoparticles were characterized by XRD, FT-IR, and UV-Vis methods. For XRD and FTIR analysis, any solvents present in the functionalized tin (IV) oxide nanoparticles were evaporated and the solid product was dried in a vacuum oven at 100 C. for 2 hr before analysis. The functionalized SnO.sub.2 and Y:SnO.sub.2 were diluted with anhydrous ethanol to get 1.5% (m/v) of SnO.sub.2 which is suitable for blade coating directly on the perovskite.
Device Fabrication
[0150] ITO-PET substrate was cut into 68 in. pieces, and they were blown with an air gun and wiped using IPA. Those cleaned PET substrates were treated with UV-Ozone for 15 minutes immediately before the sequential deposition of PTAA, PFN, CH.sub.3NH.sub.3PbI.sub.3, and SnO.sub.2 or Y:SnO.sub.2 dispersion by blade coating inside a dry box. A PTAA solution was prepared by dissolving 8 mg of PTAA in 1 mL of toluene. A 60 L of the PTAA solution was used for blade coating with a blade gap of 100 m at a coating speed of 10 mm/s, followed by heating at 100 C. for 10 min and then cooled down to room temperature. Next, 60 L of a 0.4 mg/mL PFN solution in methanol was blade-coated on the PTAA layer at a coating speed of 10 mm/s with a blade gap of 100 m. The perovskite precursor solution was prepared by dissolving methylammonium iodide and lead iodide in a mixture of DMF/DMSO/NMP with a volume ratio of 0.91:0.07:0.02 to get a 1.2 M solution. 70 L of the perovskite precursor solution was deposited by blade coating with a blade gap of 150 m and at a coating speed of 10 mm/s. Immediately after the deposition of perovskite precursor solution, the wet film was predried using an N.sub.2 air knife, followed by hotplate annealing at 140 C. for 2 min. Finally, 60 L of the SnO.sub.2-A or Y: SnO.sub.2-A dispersion in anhydrous ethanol was deposited on the perovskite with a blade gap height of 100 m and at a coating speed of 10 mm/s, followed by annealing at 100 C. for 2 to 3 min. The fabrication of PSCs having a device architecture of PET-ITO/PTAA/PFN/CH.sub.3NH.sub.3PbI.sub.3/BCP/SnO.sub.2-A/Ag and PET-ITO/PTAA/PFN/CH.sub.3NH.sub.3PbI.sub.3/BCP/Y: SnO.sub.2-A/Ag and an active area of 0.1 cm.sup.2 were completed by depositing 5 nm of BCP and 100 nm of silver employing thermal evaporation.
Physical Methods
[0151] X-ray photoelectron spectroscopy (XPS): VG Scientific MultiLab 3000
[0152] Energy Dispersive X-ray Spectrometry (EDS) spectra: TESCAN Vega3 SEM with EDS Detector
[0153] Powder XRD patterns were obtained using a Bruker D8 Discover X-ray diffractometer.
[0154] Infrared spectra were collected using a Thermo Nicolet Avatar 360 FT-IR spectrometer with Smart iTR.
[0155] UV-Vis analyses were carried out on a Agilent 8453 UV-Vis spectrometer.
[0156] The top section SEM images were obtained using a JEOL 7000 field-emission scanning electron microscope. PL analysis was carried out using a Renishaw in Via Raman microscope with a CCD detector and a 632 nm HeNe laser source. The current density-voltage (J-V) characteristics of devices were measured using a Class AAA solar simulator having a xenon arc lamp under 1 sun condition (AM1.5G, 100 mW/cm2). Prior to the device measurements, the solar simulator was calibrated using an NREL-certified Si reference cell. Devices were tested from 1.2 to 0 V at a scan rate of 100 mV/s with a step size of 10 mV
Example Set EYttrium Doping on SnO.SUB.2
[0157] A series of yttrium doped tin (IV) oxide (Y:SnO.sub.2) nanoparticles (NPs) were synthesized using a slight modification of the solgel process that we recently reported for the synthesis of pristine tin (IV) oxide (SnO.sub.2) particles (Chapagain et al. (2021) Direct Deposition of Nonaqueous SnO.sub.2 Dispersion by Blade Coating on Perovskites for the Scalable Fabrication of p-i-n Perovskite Solar Cells ACS Appl. Energy Mater., Vol. 4, No. 10, pp. 10477-10483). For the synthesis Y:SnO.sub.2 nanoparticles, yttrium chloride was added to aqueous solution of anhydrous SnCl.sub.4 during the synthesis process in the appropriate ratios to get 1% Y:SnO.sub.2, 2% Y:SnO.sub.2, and 3% Y:SnO.sub.2 (
[0158] To enhance dispersibility in perovskite compatible organic solvents, the Y:SnO.sub.2 NPs were functionalized with acetate to yield Y:SnO.sub.2-A. Acetate functionalization converts the amorphous, white powder of Y:SnO.sub.2 to a clear and colorless solution of functionalized tin oxide (Y:SnO.sub.2-A) in glacial acetic acid. Here, as shown in
[0159] The photovoltaic performance of the perovskite solar cells vs concentration Y:SnO.sub.2 is presented in
Example Set F
[0160] Perovskite ink was prepared by dissolving PbI.sub.2 and MAI in dimethyl sulfoxide (DMSO, 7%), N-methyl-2-pyrrolidone (NMP, 2%), and dimethylformamide (DMF, 91%) to make a 1.2M solution by gentle stirring. The perovskite was deposited on PET by blade coating with a blade gap of 100 m at a speed of 10 mm sec.sup.1 at room temperature. After perovskite deposition, the films were dried with a N.sub.2 knife at a pressure of 40 psi prior to annealing at 140 C. for 2 minutes. The NiO.sub.x inks were prepared by sonication of NiO.sub.x particles (20 mg) in 200 L of a 3:1 (v/v) Et.sub.3N/EtOH mixture for 60 minutes at 65 C. in a closed vial. The resulting suspension was diluted with 700 L CB and 100 L EtOH to make a 20 mg/mL NiO.sub.x solution. After dilution, the suspensions were sonicated with heating at 65 C. The hot ink suspensions were filtered through 0.2 m PTFE prior to blade coating. 40 L inch.sup.2 of the NiO.sub.x inks were deposited on the perovskite by blade coating using an optimized blade gap of 225 m at a speed of 5 mm sec.sup.1.
[0161] Results with neat NiO.sub.x (no added PA) confirm successful solution phase deposition on perovskite. The XRD pattern (
[0162] The headings used in the disclosure are not meant to suggest that all disclosure relating to the heading is found within the section that starts with that heading. Disclosure for any subject may be found throughout the specification.
[0163] It is noted that terms like preferably, commonly, and typically are not used herein to limit the scope of the claimed invention or to imply that certain features are critical, essential, or even important to the structure or function of the claimed invention. Rather, these terms are merely intended to highlight alternative or additional features that may or may not be utilized in a particular embodiment of the present invention.
[0164] As used in the disclosure, a or an means one or more than one, unless otherwise specified. As used in the claims, when used in conjunction with the word comprising the words a or an means one or more than one, unless otherwise specified. As used in the disclosure or claims, another means at least a second or more, unless otherwise specified. As used in the disclosure, the phrases such as, for example, and e.g. mean for example, but not limited to in that the list following the term (such as, for example, or e.g.) provides some examples but the list is not necessarily a fully inclusive list. The word comprising means that the items following the word comprising may include additional unrecited elements or steps; that is, comprising does not exclude additional unrecited steps or elements.
[0165] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term about. Accordingly, unless indicated to the contrary, the numerical parameters set forth in this specification and claims are approximations that can vary depending upon the desired properties sought to be obtained by the presently-disclosed subject matter.
[0166] As used herein, the term about, when referring to a value or to an amount of mass, weight, time, volume, concentration or percentage is meant to encompass variations of in some embodiments 20%, in some embodiments 10%, in some embodiments 5%, in some embodiments 1%, in some embodiments 0.5%, and in some embodiments 0.1% from the specified amount, as such variations are appropriate to perform the disclosed method.
[0167] Detailed descriptions of one or more embodiments are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein (even if designated as preferred or advantageous) are not to be interpreted as limiting, but rather are to be used as an illustrative basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in any appropriate manner. Indeed, various modifications of the invention in addition to those described herein will become apparent to those skilled in the art from the foregoing description and the accompanying figures. Such modifications are intended to fall within the scope of the appended claims.