ORGANIC-INORGANIC PEROVSKITE SOLAR CELL WITH DIRECTIONAL ARRANGEMENT OF INTRINSIC PEROVSKITE DIPOLES AND PREPARATION METHOD THEREOF

Abstract

An organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles is provided, and includes a conductive substrate, an electron transport layer, a perovskite film with directional arrangement of intrinsic dipoles, a hole transport layer and a metal counter electrode arranged from bottom to top; or the conductive substrate, the perovskite film with directional arrangement of intrinsic dipoles, the hole transport layer and the metal counter electrode arranged from bottom to top; a preparation method of the perovskite film includes: adding sulfonamide into perovskite precursor solution, and evenly mixing; spin coating on the electron transport layer or the conductive substrate and annealing. Volatile and high-polar molecule sulfonamide is used as an initiator for directional arrangement of intrinsic perovskite dipoles to induce reorientation of perovskite dipoles, thus achieving vertical directional polarization of the perovskite film, and effectively improve photoelectric conversion efficiency and stability of solar cells.

Claims

1. An organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles, wherein the organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles comprises: a conductive substrate, an electron transport layer, a perovskite film with directional arrangement of intrinsic dipoles, a hole transport layer, and a metal counter electrode, which are sequentially arranged from bottom to top; and a preparation method of the perovskite film with directional arrangement of intrinsic dipoles comprises: adding sulfonamide (SO.sub.2(NH.sub.2).sub.2) into a precursor solution of perovskite and evenly mixing to obtain a spin-coating solution, spin coating the spin-coating solution in the electron transport layer, and performing a first annealing treatment to obtain the perovskite film with directional arrangement of intrinsic dipoles; or wherein the organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles comprises: the conductive substrate, the perovskite film with directional arrangement of intrinsic dipoles, the hole transport layer, and the metal counter electrode, which are sequentially arranged from bottom to top; and the preparation method of the perovskite film with directional arrangement of intrinsic dipoles comprises: adding sulfonamide into the precursor solution of perovskite and evenly mixing to obtain the spin-coating solution, spin coating the spin-coating solution in the conductive substrate, and performing the first annealing treatment to obtain the perovskite film with directional arrangement of intrinsic dipoles.

2. The organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles as claimed in claim 1, wherein at least one of the following conditions is satisfied: the conductive substrate is a transparent conductive substrate with fluorine-doped tin oxide (FTO), and a thickness of the conductive substrate is in a range of 140-160 nanometers (nm); a material of the electron transport layer is tin dioxide (SnO.sub.2), and a thickness of the electron transport layer is in a range of 30-50 nm; a material of the hole transport layer is 2,2,7,7-tetrakis[N,N-di(4-methoxyphenyl) amino]-9,9-spirobifluorene (spiro-OMeTAD), and a thickness of the hole transport layer is in a range of 200-250 nm; or the metal counter electrode is a silver (Ag) counter electrode, and a thickness of the metal counter electrode is in a range of 100-140 nm.

3. The organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles as claimed in claim 1, wherein a thickness of the perovskite film with directional arrangement of intrinsic dipoles is in a range of 550-600 nm, the perovskite film with directional arrangement of intrinsic dipoles has a gradient energy band structure, and transits from a p-type semiconductor to a n-type semiconductor from bottom to top in the gradient energy band structure.

4. The organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles as claimed in claim 1, wherein a preparation method of the precursor solution of perovskite comprises dissolving crystal of formamidine lead iodine (FAPbI.sub.3) powder and methylamine chloride (MACl) in a mixed solvent of N, N-dimethylformamide (C.sub.3H.sub.7NO) and dimethyl sulfoxide (C.sub.2H.sub.6OS) to obtain the precursor solution of perovskite, and a mole ratio of the FAPbI.sub.3 powder and the MACl is 1:0.35; in the mixed solvent, a volume ratio of the N, N-dimethylformamide and the dimethyl sulfoxide is 3-5:1; and a concentration of the FAPbI.sub.3 powder in the mixed solvent is in a range of 1.6-1.8 moles per liter (mol/L); and wherein a preparation method of the crystal of FAPbI.sub.3 powder comprises mixing lead acetate ((CH.sub.3COO).sub.2Pb) with formamidine acetate (C.sub.3H.sub.8N.sub.2O.sub.2) in a mole ratio of 3:4 and adding into hydroiodic acid (HI) aqueous solution, keeping a temperature of 80-90 Celsius degree (? C.) for 2-4 hours (h), and performing a washing treatment and a second annealing treatment to obtain the single crystal FAPbI.sub.3 powder; and a concentration of the hydroiodic acid aqueous solution is in a range of 55-58 weight percent (wt %), a temperature of the second annealing treatment is in a range of 150-180? C., and a period of the second annealing treatment is in a range of 12-24 h.

5. The organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles as claimed in claim 1, wherein a mole ratio of the sulfonamide and the formamidine lead iodine in the precursor solution of perovskite is 0.02-0.08:1.

6. The organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles as claimed in claim 5, wherein the mole ratio of the sulfonamide and the formamidine lead iodine in the precursor solution of perovskite is 0.04:1.

7. The organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles as claimed in claim 1, wherein a speed for spin coating the spin-coating solution is in a range of 5000-6000 revolutions per minute (rpm), and a period for spin coating the spin-coating solution is in a range of 40-50 seconds (s); wherein an ether (C.sub.2H.sub.5OC.sub.2H.sub.5) antisolvent is added when the spin coating is performed for 10 s, and a volume ratio of the ether antisolvent and the spin-coating solution is 10-13:1.

8. The organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles as claimed in claim 1, wherein a temperature of the first annealing treatment is in a range of 100-160? C., and a period of the first annealing treatment is in a range of 10-15 minutes (min).

9. The organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles as claimed in claim 8, wherein the temperature of the first annealing treatment is in a range of 140-160? C.

10. The organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles as claimed in claim 1, wherein the spin coating and the first annealing treatment are performed in an atmosphere with a protective gas, and the protective gas is nitrogen.

11. The organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles as claimed in claim 1, wherein the perovskite film with directional arrangement of intrinsic dipoles is a formamidine lead iodo perovskite or a methylamine lead iodo perovskite.

12. A preparation method of organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles as claimed in claim 1, comprising: step 1: pretreating the conductive substrate; step 2: preparing the electron transport layer on the conductive substrate, and preparing the perovskite film with directional arrangement of intrinsic dipoles on the electron transport layer; or directly preparing the perovskite film with directional arrangement of intrinsic dipoles on the conductive substrate; step 3: preparing the hole transport layer on the perovskite film with directional arrangement of intrinsic dipoles; and step 4: preparing the metal counter electrode on the hole transport layer.

13. The preparation method of organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles as claimed in claim 12, at least one of the following conditions is satisfied: in step 1, a method for the pretreating the conductive substrate comprises: sequentially performing an ultrasonic cleaning process of the conductive substrate in deionized water, isopropanol (C.sub.3H.sub.8O) and ethanol (CH.sub.3CH.sub.2OH), and performing blow-drying with nitrogen; and performing an ultraviolet ozone treatment on the conductive substrate; wherein a period of the ultrasonic cleaning process for each of the deionized water, the isopropanol and the ethanol is in a range of 10-20 min, and a period of the ultraviolet ozone treatment is in a range of 10-30 min; in step 2, a method for the preparing the electron transport layer on the conductive substrate comprises: submerging the conductive substrate in a mixed aqueous solution of hydrochloric acid (HCl), urea (CO(NH.sub.2).sub.2), thioglycolic acid (C.sub.2H.sub.4O.sub.2S) and tin(II) chloride dihydrate (SnCl.sub.2.Math.2H.sub.2O), and performing a washing treatment, a drying treatment and a third annealing treatment to obtain the electron transport layer; a concentration of the urea in the mixed aqueous solution is in a range of 12-13 milligrams per milliliter (mg/mL), a concentration of the hydrochloric acid is in a range of 12-13 microliters per milliliter (?L/mL) and with a mass fraction of the hydrochloric acid is 37 wt %, a concentration of the thioglycolic acid is in a range of 0.2-0.3 ?L/mL, and a concentration of SnCl.sub.2.Math.2H.sub.2O is in a range of 2.5-3 mg/mL; a temperature for the submerging is in a range of 85-95? C., a period for the submerging is in a range of 5-6 h, a temperature of the third annealing treatment is in a range of 160-180? C., a period of the third annealing treatment is in a range of 30-60 min, and an atmosphere of the third annealing treatment is air; in step 3, a method for the preparing the hole transport layer comprises: mixing spiro-OMeTAD, chlorobenzene (C.sub.6H.sub.5Cl), 4-tert-butylpyridine (C.sub.9H.sub.13N), bis (tri fluoromethane) sulfonic imide lithium salt (CF.sub.3SO.sub.2NLiSO.sub.2CF.sub.3) acetonitrile (CH.sub.3CN) solution, and 4-tert-butyl-2-(1H-pyrazole-1-yl) pyridine] cobalt (III) (C.sub.12H.sub.15N.sub.3) acetonitrile solution and performing stirring for dissolving to obtain a doped spiro-OMeTAD solution, spin coating the doped spiro-OMeTAD solution on the perovskite film with directional arrangement of intrinsic dipoles, and drying the doped spiro-OMeTAD solution to obtain the hole transport layer; and a ratio of a mass of the spiro-OMeTAD and a volume of the chlorobenzene is 90:1 mg/mL, a concentration of the bis (tri fluoromethane) sulfonic imide lithium salt acetonitrile solution is in a range of 500-540 mg/mL, a concentration of the 4-tert-butyl-2-(1H-pyrazole-1-yl) pyridine] cobalt (III) acetonitrile solution is in a range of 350-400 mg/mL, a volume ratio of the chlorobenzene:the 4-tert-butylpyridine: the bis (tri fluoromethane) sulfonic imide lithium salt acetonitrile solution:the 4-tert-butyl-2-(1H-pyrazole-1-yl) pyridine] cobalt (III) acetonitrile solution is 1000:39:23:10; a speed for spin coating the doped spiro-OMeTAD solution is in a range of 3000-4000 rpm, and a period for spin coating the doped spiro-OMeTAD solution is in a range of 20-30 s; or in step 4, a method for the preparing the metal counter electrode on the hole transport layer comprises depositing the metal counter electrode on the hole transport later by using a thermal evaporation with an evaporation rate of 0.1-0.8 angstroms per second (?/s) under a vacuum degree being smaller than 1?10.sup.?4 pascals (Pa).

Description

BRIEF DESCRIPTION OF DRAWINGS

[0039] FIG. 1 illustrates scanning electron microscope (SEM) diagrams of organic-inorganic perovskite films, in which (a), (b), (c), and (d) respectively correspond to the organic-inorganic perovskite films prepared in a comparative embodiment 1, an embodiment 3, an embodiment 1, and an embodiment 4 of the disclosure.

[0040] FIG. 2 illustrates phase diagrams of a piezoelectric force microscope (PFM) of organic-inorganic perovskite films, in which (a) and (b) respectively correspond to the organic-inorganic perovskite films prepared in the comparative embodiment and the embodiment 1 of the disclosure, and a length of the ruler is 2 microns (m).

[0041] FIG. 3 illustrates ultraviolet photoelectron spectroscopies (UPS) of organic-inorganic perovskite films, in which (a) and (b) respectively correspond to the organic-inorganic perovskite films prepared in the comparative embodiment 1 and the embodiment 1 of the disclosure at different depths.

[0042] FIG. 4 illustrates schematic diagrams of a structure model and a current density-voltage curve of a solar cell prepared in the embodiment 1 of the disclosure.

[0043] FIG. 5 illustrates a schematic diagram showing stability tests of solar cells prepared in the embodiment 1 and solar cells prepared in the comparative embodiment 1 of the disclosure.

[0044] FIG. 6 illustrates schematic diagrams of a structure model and a current density-voltage curve of a solar cell prepared in an embodiment 2 of the disclosure.

[0045] FIG. 7 illustrates a schematic diagram showing stability test results for solar cells prepared in the embodiment 2 and solar cells prepared in a comparative embodiment 2 of the disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

[0046] The disclosure will be further described in conjunction with embodiments, but not limited to them.

[0047] Unless otherwise specified, raw materials used in the embodiments are all conventional and commercially available; unless otherwise specified, methods used in the embodiments, are all the related art.

Embodiment 1

[0048] A preparation method of organic-inorganic perovskite solar cells with directional arrangement of intrinsic perovskite dipoles is provided, and the method includes the following steps 1-5.

[0049] In step 1, an ultrasonic cleaning process is performed on a fluorine-doped tin oxide (FTO) transparent conductive substrate (a length?width is 19?24 square millimeters (mm.sup.2), and a thickness is 150 nanometers (nm)) sequentially in deionized water, isopropanol (C.sub.3H.sub.8O) and ethanol (CH.sub.3CH.sub.2OH) solution. A period of the ultrasonic cleaning process for each of the deionized water, the isopropanol, and the ethanol is 15 minutes (min), blow-drying is performed on the conductive substrate with nitrogen gas and then is processed under an ultraviolet ozone condition for 20 min, and thus a pretreated FTO transparent conductive substrate is obtained.

[0050] In step 2, urea (CO(NH.sub.2).sub.2) with a concentration of 12.5 milligrams per milliliter (mg/mL), hydrochloric acid (HCl) with a concentration of 12.5 microliters per milliliter (?L/mL), thioglycolic acid (C.sub.2H.sub.4O.sub.2S) with a concentration of 0.25 ?L/mL, and tin (II) chloride dihydrate (SnCl.sub.2.Math.2H.sub.2O) with a concentration of 2.75 mg/mL are will-mixed in the deionized water to obtain a precursor solution. The pretreated FTO transparent conductive substrate is submerged in the precursor solution, and a temperature of 90 Celsius degree (? C.) is kept for 5.5 hours (h) to deposit a tin dioxide electron transport layer to thus obtain a cell substrate. The ultrasonic cleaning process is performed on the cell substrate sequentially in the deionized water and the ethanol solution for 3 min, and blow-drying is performed on the cell substrate with the nitrogen gas and is performed an annealing treatment in air at a temperature of 170? C. for 60 min to prepared the electron transport layer with a thickness of 40 nm.

[0051] In step 3, a preparation method of the crystal of formamidine lead iodine (FAPbI.sub.3) is as follows. 1.5 moles (mol) of lead acetate ((CH.sub.3COO).sub.2Pb) and 2 mol of formamidine acetate (C.sub.3H.sub.8N.sub.2O.sub.2) are mixed and added in 5 milliliters (mL) of hydroiodic acid (HI) aqueous solution with a concentration of 57 weight percent (wt %), a temperature of 80? C. is kept for 3 h to obtain a black FAPbI.sub.3, and a washing treatment and an annealing treatment are performed on the black FAPbI.sub.3 to obtain the FAPbI.sub.3 crystal; and a temperature of the annealing treatment is 150? C., and a period of the annealing treatment is 18 h.

[0052] The FAPbI.sub.3 crystal, methylamine chloride (MACl), and sulfonamide are dissolved according to a mole ratio of 1:0.35:0.04, in a mixed solvent of N, N-dimethylformamide (C.sub.3H.sub.7NO) and dimethyl sulfoxide (C.sub.2H.sub.6OS) (a volume ratio of the N, N-dimethylformamide, and dimethyl sulfoxide is 4:1) to obtain a precursor solution, and stirred at a temperature of 40? C. for 4 h, specifically, a concentration of the FAPbI.sub.3 is 1.8 moles per liter (mol/L). Inside a nitrogen-protected glove box, the pipette is used to transfer 70 ?L of the prepared precursor solution, and the prepared precursor solution is evenly spin-coated on the electron transport layer prepared in step 2 by a spin coater; specifically, a speed for spin coating the precursor solution is 6000 revolutions per minute (rpm), a period for spin coating the precursor solution is 50 seconds (s), and 800 ?L of ether (C.sub.2H.sub.5OC.sub.2H.sub.5) antisolvent is added when the spin coating is performed for 10 s. And after spin coating, an annealing treatment is performed at a temperature of 150? C. for 10 min in a nitrogen atmosphere to prepare and obtain a perovskite film with directional arrangement of intrinsic dipoles, and a thickness of the perovskite film is 560 nm.

[0053] In step 4, 90 milligrams (mg) of 2,2,7,7-tetrakis-[N,N-di-(4-methoxyphenyl) amino]-9,9-spirobifluorene (spiro-OMeTAD), 39 ?L of 4-tert butyl pyridine (C.sub.9H.sub.13N), 23 ?L of bis (tri-fluoromethane) sulfonic imide lithium salt (CF.sub.3SO.sub.2NLiSO.sub.2CF.sub.3) acetonitrile solution (a weight concentration is 520 mg/mL), 10 ?L of 4-tert-butyl-2-(1H-pyrazole-1-yl) pyridine] cobalt (III) (C.sub.12H.sub.15N.sub.3) acetonitrile solution (a weight concentration is 375 mg/mL), and 1 mL of chlorobenzene (C.sub.6H.sub.5Cl) solution are mixed and stirred at a room temperature for 12 h to obtain a doped spiro-OMeTAD solution. And the doped spiro-OMeTAD solution is spin coated in a surface of the perovskite film with directional arrangement of intrinsic dipoles, and dried to obtain a hole transport layer, a speed for spin coating the doped spiro-OMeTAD solution is 3500 rpm, a period for spin coating the doped spiro-OMeTAD solution is 25 s, and a thickness of a prepared hole transport layer is 200 nm.

[0054] In step 5, a silver (Ag) electrode layer with a thickness of 120 nm is deposited on the hole transport layer by evaporating with an evaporation rate of 0.1-0.8 angstroms per second (?/s) under a vacuum degree smaller than 1?10.sup.?4 pascal (Pa), to fabricating an organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles.

[0055] A scanning electron microscope (SEM) diagram of a perovskite film with directional arrangement of intrinsic dipoles prepared in step 3 of the embodiment 1 is shown in (c) of FIG. 1. As shown in (a)-(d) of FIG. 1, an organic-inorganic perovskite added with the sulfonamide shows a uniform morphology, and shows an increasing grain size compared to a comparative embodiment 1.

[0056] A phase diagram of a piezoelectric force microscope (PFM) of the perovskite film with directional arrangement of intrinsic dipoles prepared in the step 3 of the embodiment 1 is shown in (b) of FIG. 2. From a phase distribution in (a)-(b) of FIG. 2, it can be seen that compared to a single distribution of phase for the comparative embodiment 1, an internal area of the grain of the organic-inorganic perovskite modified by the sulfonamide shows an additional polarization of vertical orientation.

[0057] An ultraviolet photoelectron spectroscopy (UPS) of the perovskite film with directional arrangement of intrinsic dipoles prepared in the step 3 of the embodiment 1 is shown in (b) of FIG. 3. With an increase of depth, that closes to the electron transport layer, a work function of the perovskite film is gradually decreasing. The perovskite film with directional arrangement of intrinsic dipoles is provided with a transition from a p-type semiconductor to a n-type semiconductor, which shows a gradient energy band structure, however, a perovskite film prepared in the comparative embodiment 1 shows a similar energy band structure in different depths.

[0058] A structure and a current density-voltage curve of a solar cell prepared in the embodiment 1 are as shown in FIG. 4, in a standard testing condition (lighting with air mass (AM) 1.5), and in a reverse scanning of a cell device with directional arrangement of dipoles, a photoelectric conversion efficiency is 24.63 percent (%), an open current voltage is 1.159 volts (V), a short circuit current is 25.46 milliamperes per square centimeter (mA/cm.sup.2), and a fill factor is 83.48%; in a forward scanning, the photoelectric conversion efficiency is 24.17%, the open current voltage is 1.153 V, the short circuit current is 25.34 mA/cm.sup.2, and the fill factor is 82.71%. Significantly increased compared to the comparative embodiment 1.

[0059] A stability test result of perovskite solar cells without encapsulation prepared in the embodiment 1 is shown in FIG. 5. After storing at a temperature of 25? C., a relative humidity of 20%, an air environment, and a dark condition for 1080 h, the perovskite solar cells without encapsulation can maintain an initial efficiency of over 93%, significantly improved compared to the comparative embodiment 1.

Embodiment 2

[0060] A preparation method of organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles is described in the embodiment 1, the difference is that the step 2 is omitted, that is the perovskite film with directional arrangement of intrinsic dipoles is directly deposited on the pretreated FTO transparent conductive substrate.

[0061] Other steps and conditions are consistent with the embodiment 1.

[0062] A structure and a current density-voltage curve of a solar cell prepared in the embodiment 2 are shown in FIG. 6, in the standard testing condition (lighting with AM 1.5), and in a situation of reverse scanning of the cell device with directional arrangement of dipoles, the photoelectric conversion efficiency is 20.37%, the open current voltage is 1.063 V, the short circuit current is 24.58 mA/cm.sup.2, and the fill factor is 77.95%; in a situation of forward scanning, the photoelectric conversion efficiency is 19.56%, the open current voltage is 1.054 V, the short circuit current is 24.36 mA/cm.sup.2, and the fill factor is 76.18%, which is one of the highest efficiencies of perovskite solar cells without the electron transport layer reported currently.

[0063] A stability test result of perovskite solar cells without encapsulation prepared in the embodiment 1 is shown in FIG. 7. After storing at a temperature of 25? C., a relative humidity of 20%, an air environment, and a dark condition for 1080 h, the perovskite solar cells without encapsulation can maintain an initial efficiency of over 90%, significantly improved of device stability compared to a comparative embodiment 2.

[0064] It is noted that the perovskite film prepared in the embodiment 2 is the same as the embodiment 1, a polarization of the perovskite film and relative information of the energy band are the same as the embodiment 1, and no further repetition of the narrative.

Embodiment 3

[0065] A preparation method of organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles is described in the embodiment 1, it is different in step 3 in that, the FAPbI.sub.3 crystal, the MACl, and the sulfonamide are dissolved according to a mole ratio of 1:0.35:0.02, in the mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide (the volume ratio of the N, N-dimethylformamide and dimethyl sulfoxide is 4:1) to obtain the precursor solution, and stirred at a temperature of 40? C. for 4 h, specifically, a concentration of the FAPbI.sub.3 is 1.8 mol/L. Inside a nitrogen-protected glove box, the pipette is used to transfer 70 ?L of the prepared precursor solution, and the prepared precursor solution is evenly spin-coated on the electron transport layer prepared in the step 2 by the spin coater; specifically, the speed for spin coating the precursor solution is 6000 rpm, the period for spin coating the precursor solution is 50 s, and 800 ?L of the ether antisolvent is added when the spin coating is performed for 10 s. And after spin coating, the annealing treatment is performed at a temperature of 150? C. for 10 min in the nitrogen atmosphere to prepare and obtain the perovskite film with directional arrangement of intrinsic dipoles.

[0066] Other steps and conditions are consistent with the embodiment 1.

[0067] A SEM diagram of a perovskite film with directional arrangement of intrinsic dipoles prepared in step 3 of the embodiment 3 is shown in (b) of FIG. 1. As shown in (a)-(d) of FIG. 1, an organic-inorganic perovskite modified by the sulfonamide shows a uniform morphology, and shows an increasing grain size compared to the comparative embodiment 1.

[0068] A solar cell prepared in the embodiment 3 in the standard testing condition (lighting with AM 1.5), and in a situation of reverse scanning, the photoelectric conversion efficiency is 24.08%, the open current voltage is 1.141 V, the short circuit current is 25.42 mA/cm.sup.2, and the fill factor is 83.02%; in a situation of forward scanning, the photoelectric conversion efficiency is 23.42%, the open current voltage is 1.137 V, the short circuit current is 25.26 mA/cm.sup.2, and the fill factor is 81.54%. The photoelectric conversion efficiency is improved compared to the comparative embodiment 1, slightly decreased compared to the embodiment 1.

Embodiment 4

[0069] A preparation method of organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles is described in the embodiment 1, it is different in step 3 in that, the FAPbI.sub.3 crystal, the MACl, and the sulfonamide are dissolved according to a mole ratio of 1:0.35:0.08, in the mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide (the volume ratio of the N, N-dimethylformamide and dimethyl sulfoxide is 4:1) to obtain the precursor solution, and stirred at a temperature of 40? C. for 4 h, specifically, a concentration of the FAPbI.sub.3 is 1.8 mol/L. Inside a nitrogen-protected glove box, the pipette is used to transfer 70 ?L of the prepared precursor solution, and the prepared precursor solution is evenly spin-coated on the electron transport layer prepared in the step 2 by the spin coater; specifically, the speed for spin coating the precursor solution is 6000 rpm, the period for spin coating the precursor solution is 50 s, and 800 ?L of the ether antisolvent is added when the spin coating is performed for 10 s. And after spin coating, the annealing treatment is performed at a temperature of 150? C. for 10 min in the nitrogen atmosphere to prepare and obtain the perovskite film with directional arrangement of intrinsic dipoles.

[0070] Other steps and conditions are consistent with the embodiment 1.

[0071] A SEM diagram of a perovskite film with directional arrangement of intrinsic dipoles prepared in step 3 of the embodiment 4 is shown in (d) of FIG. 1. As shown in (a)-(d) of FIG. 1, an organic-inorganic perovskite modified by the sulfonamide shows a uniform morphology, and shows an increasing grain size compared to the comparative embodiment 1.

[0072] A solar cell prepared in the embodiment 4 in the standard testing condition (lighting with AM 1.5), and in a situation of reverse scanning, the photoelectric conversion efficiency is 23.83%, the open current voltage is 1.138 V, the short circuit current is 25.31 mA/cm.sup.2, and the fill factor is 82.74%; in a situation of forward scanning, the photoelectric conversion efficiency is 23.41%, the open current voltage is 1.132 V, the short circuit current is 25.25 mA/cm.sup.2, and the fill factor is 81.90%. The photoelectric conversion efficiency is improved compared to the comparative embodiment 1, slightly decreased compared to the embodiment 1 and the embodiment 3.

Embodiment 5

[0073] A preparation method of organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles is described in the embodiment 2, it is different in step 3 in that, the FAPbI.sub.3 crystal, the MACl, and the sulfonamide are dissolved according to a mole ratio of 1:0.35:0.02, in the mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide (the volume ratio of the N, N-dimethylformamide and dimethyl sulfoxide is 4:1) to obtain the precursor solution, and stirred at a temperature of 40? C. for 4 h, specifically, a concentration of the FAPbI.sub.3 is 1.8 mol/L. Inside a nitrogen-protected glove box, the pipette is used to transfer 70 ?L of the prepared precursor solution, and the prepared precursor solution is evenly spin-coated on the FTO transparent conductive substrate pretreated in the step 1 by the spin coater; specifically, the speed for spin coating the precursor solution is 6000 rpm, the period for spin coating the precursor solution is 50 s, and 800 ?L of the ether antisolvent is added when the spin coating is performed for 10 s. And after spin coating, the annealing treatment is performed at a temperature of 150? C. for 10 min in the nitrogen atmosphere to prepare and obtain the perovskite film with directional arrangement of intrinsic dipoles.

[0074] Other steps and conditions are consistent with the embodiment 2.

[0075] A solar cell prepared in the embodiment 5 in the standard testing condition (lighting with AM 1.5), and in a situation of reverse scanning, the photoelectric conversion efficiency is 19.61%, the open current voltage is 1.043 V, the short circuit current is 24.44 mA/cm.sup.2, and the fill factor is 76.92%; in a situation of forward scanning, the photoelectric conversion efficiency is 18.89%, the open current voltage is 1.035 V, the short circuit current is 24.21 mA/cm.sup.2, and the fill factor is 75.37%. The photoelectric conversion efficiency is improved compared to the comparative embodiment 2, slightly decreased compared to the embodiment 2.

Embodiment 6

[0076] A preparation method of organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles is described in the embodiment 2, it is different in step 3 in that, the FAPbI.sub.3 crystal, the MACl, and the sulfonamide are dissolved according to a mole ratio of 1:0.35:0.08, in the mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide (the volume ratio of the N, N-dimethylformamide and dimethyl sulfoxide is 4:1) to obtain the precursor solution, and stirred at a temperature of 40? C. for 4 h, specifically, a concentration of the FAPbI.sub.3 is 1.8 mol/L. Inside a nitrogen-protected glove box, the pipette is used to transfer 70 ?L of the prepared precursor solution, and the prepared precursor solution is evenly spin-coated on the FTO transparent conductive substrate pretreated in the step 1 by the spin coater; specifically, the speed for spin coating the precursor solution is 6000 rpm, the period for spin coating the precursor solution is 50 s, and 800 ?L of the ether antisolvent is added when the spin coating is performed for 10 s. And after spin coating, the annealing treatment is performed at a temperature of 150? C. for 10 min in the nitrogen atmosphere to prepare and obtain the perovskite film with directional arrangement of intrinsic dipoles.

[0077] Other steps and conditions are consistent with the embodiment 2.

[0078] A solar cell prepared in the embodiment 6 in the standard testing condition (lighting with AM 1.5), and in a situation of reverse scanning, the photoelectric conversion efficiency is 18.99%, the open current voltage is 1.045 V, the short circuit current is 24.05 mA/cm.sup.2, and the fill factor is 75.58%; in a situation of forward scanning, the photoelectric conversion efficiency is 18.29%, the open current voltage is 1.032 V, the short circuit current is 23.88 mA/cm.sup.2, and the fill factor is 74.23%. The photoelectric conversion efficiency is improved compared to the comparative embodiment 2, slightly decreased compared to the embodiment 2 and the embodiment 5, and a hysteresis is slightly improved compared to the embodiment 5.

Embodiment 7

[0079] A preparation method of organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles is described in the embodiment 1, it is different in step 3 in that the temperature of the annealing treatment of the perovskite film is changed. The FAPbI.sub.3 crystal, the MACl, and the sulfonamide are dissolved according to a mole ratio of 1:0.35:0.04, in the mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide (the volume ratio of the N, N-dimethylformamide and dimethyl sulfoxide is 4:1) to obtain the precursor solution, and stirred at a temperature of 40? C. for 4 h, specifically, the concentration of the FAPbI.sub.3 is 1.8 mol/L. Inside a nitrogen-protected glove box, the pipette is used to transfer 70 ?L of the prepared precursor solution, and the prepared precursor solution is evenly spin-coated on the electron transport layer prepared in the step 2 by the spin coater; specifically, the speed for spin coating the precursor solution is 6000 rpm, the period for spin coating the precursor solution is 50 s, and 800 ?L of the ether antisolvent is added when the spin coating is performed for 10 s. And after spin coating, the annealing treatment is performed at a temperature of 100? C. for 15 min in the nitrogen atmosphere to prepare and obtain the perovskite film with directional arrangement of intrinsic dipoles.

[0080] Other steps and conditions are consistent with the embodiment 1.

[0081] A solar cell prepared in the embodiment 7 in the standard testing condition (lighting with AM 1.5), and in a situation of reverse scanning, the photoelectric conversion efficiency is 24.04%, the open current voltage is 1.139 V, the short circuit current is 25.45 mA/cm.sup.2, and the fill factor is 82.93%; in a situation of forward scanning, the photoelectric conversion efficiency is 23.37%, the open current voltage is 1.134 V, the short circuit current is 25.28 mA/cm.sup.2, and the fill factor is 81.52%. The photoelectric conversion efficiency is improved compared to the comparative embodiment 1, slightly decreased compared to the embodiment 1.

Embodiment 8

[0082] A preparation method of organic-inorganic perovskite solar cell with directional arrangement of intrinsic perovskite dipoles is described in the embodiment 2, it is different in step 3 in that the temperature of the annealing treatment of the perovskite film is changed. The FAPbI.sub.3 crystal, the MACl, and the sulfonamide are dissolved according to a mole ratio of 1:0.35:0.04, in the mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide (the volume ratio of the N, N-dimethylformamide and dimethyl sulfoxide is 4:1) to obtain the precursor solution, and stirred at a temperature of 40? C. for 4 h, specifically, the concentration of the FAPbI.sub.3 is 1.8 mol/L. Inside a nitrogen-protected glove box, the pipette is used to transfer 70 ?L of the prepared precursor solution, and the prepared precursor solution is evenly spin-coated on the FTO transparent conductive substrate pretreated in the step 1 by the spin coater; specifically, the speed for spin coating the precursor solution is 6000 rpm, the period for spin coating the precursor solution is 50 s, and 800 ?L of the ether antisolvent is added when the spin coating is performed for 10 s. And after spin coating, the annealing treatment is performed at the temperature of 100? C. for 15 min in the nitrogen atmosphere to prepare and obtain the perovskite film with directional arrangement of intrinsic dipoles.

[0083] Other steps and conditions are consistent with the embodiment 2.

[0084] A solar cell prepared in the embodiment 8 in the standard testing condition (lighting with AM 1.5), and in a situation of reverse scanning, the photoelectric conversion efficiency is 19.74%, the open current voltage is 1.058 V, the short circuit current is 24.34 mA/cm.sup.2, and the fill factor is 76.67%; in a situation of forward scanning, the photoelectric conversion efficiency is 18.98%, the open current voltage is 1.047 V, the short circuit current is 24.13 mA/cm.sup.2, and the fill factor is 75.12%. The photoelectric conversion efficiency is improved compared to the comparative embodiment 2, slightly decreased compared to the embodiment 2.

[0085] Thus, the temperature of the annealing treatment of the perovskite film is an important factor in determining a volatilization rate of the sulfonamide, a reactivity of dipole redirection is improved by a high temperature for performing the annealing treatment, which is conducive to the directional arrangement of dipoles. However, an excessively high temperature for performing the annealing treatment is not conducive to a stability of organic compounds of the perovskite film, and a specific parameter for performing the annealing treatment of the perovskite film in the disclosure is to anneal at a temperature of 150? C. for 10 min.

Comparative Embodiment 1

[0086] A preparation method for organic-inorganic perovskite solar cell is described in the embodiment 1, it is different in step 3, the sulfonamide is not added, that is: the FAPbI.sub.3 crystal and the MACl are dissolved according to a mole ratio of 1:0.35, in the mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide (the volume ratio of the N, N-dimethylformamide and dimethyl sulfoxide is 4:1) to obtain the precursor solution, and stirred at the temperature of 40? C. for 4 h, specifically, the concentration of the FAPbI.sub.3 is 1.8 mol/L. Inside a nitrogen-protected glove box, the pipette is used to transfer 70 ?L of the prepared precursor solution, and the prepared precursor solution is evenly spin-coated on the electron transport layer prepared in the step 2 by the spin coater; specifically, the speed for spin coating the precursor solution is 6000 rpm, the period for spin coating the precursor solution is 50 s, and 800 ?L of the ether antisolvent is added when the spin coating is performed for 10 s. And after spin coating, the annealing treatment is performed at the temperature of 150? C. for 10 min in the nitrogen atmosphere to prepare and obtain the perovskite film.

[0087] Other steps and conditions are consistent with the embodiment 1.

[0088] An SEM diagram of a perovskite film prepared in step 3 of the comparative embodiment 1 is shown in (a) of FIG. 1. As shown in (a)-(d) of FIG. 1, a grain size of the organic-inorganic perovskite without the sulfonamide is small and non-uniform.

[0089] A phase diagram of a PFM of the perovskite film prepared in the step 3 of the comparative embodiment 1 is shown in (a) of FIG. 2. From a phase distribution in (a)-(b) of FIG. 2, it can be seen that a phase distribution of the perovskite film is normal at 127 degrees (?).

[0090] A UPS of the perovskite film prepared in the step 3 of the comparative embodiment 1 is shown in (a) of FIG. 3. With a change of depth, the surface work function of the perovskite film and a band edge position remains basically unchanged, and shows a flat energy band structure.

[0091] A solar cell prepared in the comparative embodiment 1 in the standard testing condition (lighting with AM 1.5), in a situation of reverse scanning, the photoelectric conversion efficiency is 22.30%, the open current voltage is 1.102 V, the short circuit current is 25.03 mA/cm.sup.2, and a fill factor is 80.84%; in a situation of forward scanning, the photoelectric conversion efficiency is 21.23%, the open current voltage is 1.087 V, the short circuit current is 24.80 mA/cm.sup.2, and the fill factor is 78.77%.

[0092] A stability test result of perovskite solar cells without encapsulation prepared in the embodiment 1 is shown in FIG. 5. After storing at a temperature of 25? C., a relative humidity of 20%, an air environment, and a dark condition for 1080 h, the perovskite solar cells without encapsulation merely maintain an initial efficiency of 82%.

Comparative Embodiment 2

[0093] A preparation method for organic-inorganic perovskite solar cell is described in the embodiment 2, it is different in step 3, the sulfonamide is not added, that is: the FAPbI.sub.3 crystal, the MACl are dissolved according to a mole ratio of 1:0.35, in the mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide (the volume ratio of the N, N-dimethylformamide and dimethyl sulfoxide is 4:1) to obtain the precursor solution, and stirred at the temperature of 40? C. for 4 h, specifically, the concentration of the FAPbI.sub.3 is 1.8 mol/L. Inside a nitrogen-protected glove box, the pipette is used to transfer 70 ?L of the prepared precursor solution, and the prepared precursor solution is evenly spin-coated on the FTO transparent conductive substrate pretreated in the step 1 by the spin coater; specifically, the speed for spin coating the precursor solution is 6000 rpm, the period for spin coating the precursor solution is 50 s, and 800 ?L of the ether antisolvent is added when the spin coating is performed for 10 s. And after spin coating, the annealing treatment is performed at the temperature of 150? C. for 10 min in the nitrogen atmosphere to prepare and obtain the perovskite film.

[0094] Other steps and conditions are consistent with the embodiment 2.

[0095] A solar cell prepared in the comparative embodiment 2 in the standard testing condition (lighting with AM 1.5), in a situation of reverse scanning, the photoelectric conversion efficiency is 16.00%, the open current voltage is 0.971 V, the short circuit current is 23.85 mA/cm.sup.2, and a fill factor is 69.07%; in a situation of forward scanning, the photoelectric conversion efficiency is 12.61%, the open current voltage is 0.923 V, the short circuit current is 23.41 mA/cm.sup.2, and the fill factor is 58.34%. The photoelectric conversion efficiency is significantly decreased compared to the embodiment 2, and the comparative document 2 has a serious hysteresis.

[0096] A stability test result of perovskite solar cells without encapsulation prepared in the embodiment 1 is shown in FIG. 5. After storing at a temperature of 25? C., a relative humidity of 20%, an air environment, and a dark condition for 1080 h, the perovskite solar cells without encapsulation merely maintain an initial efficiency of 64%, and a loss of the photoelectric conversion efficiency is serious.

Comparative Embodiment 3

[0097] A preparation method for organic-inorganic perovskite solar cell is described in the embodiment 1, it is different in step 3, sulfonamide analogue is introduced, that is: the FAPbI.sub.3 crystal, the MACl, and 3,4-difluorobenzene sulfonamide (C.sub.6H.sub.5F.sub.2NO.sub.2S) are dissolved according to a mole ratio of 1:0.35:0.04, in the mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide (the volume ratio of the N, N-dimethylformamide and dimethyl sulfoxide is 4:1) to obtain the precursor solution, and stirred at the temperature of 40? C. for 4 h, specifically, the concentration of the FAPbI.sub.3 is 1.8 mol/L. Inside a nitrogen-protected glove box, the pipette is used to transfer 70 ?L of the prepared precursor solution, and the prepared precursor solution is evenly spin-coated on the electron transport layer prepared in the step 2 by the spin coater; specifically, the speed for spin coating the precursor solution is 6000 rpm, the period for spin coating the precursor solution is 50 s, and 800 ?L of the ether antisolvent is added when the spin coating is performed for 10 s. And after spin coating, the annealing treatment is performed at the temperature of 150? C. for 10 min in the nitrogen atmosphere to prepare and obtain the perovskite film.

[0098] The 3,4-difluorobenzene sulfonamide used in step 3 of the comparative embodiment 3 has a similar functional group with the sulfonamide used in the disclosure, and the 3,4-difluorobenzene sulfonamide is used as a reference in the comparative embodiment 3 to study an effect of the sulfonamide analogue to the perovskite solar cell.

[0099] Other steps and conditions are consistent with the embodiment 1.

[0100] A solar cell prepared in the comparative embodiment 3 in the standard testing condition (lighting with AM 1.5), in a situation of reverse scanning, the photoelectric conversion efficiency is 23.68%, the open current voltage is 1.133 V, the short circuit current is 25.35 mA/cm.sup.2, and a fill factor is 82.45%; in a situation of forward scanning, the photoelectric conversion efficiency is 22.76%, the open current voltage is 1.125 V, the short circuit current is 25.23 mA/cm.sup.2, and the fill factor is 80.18%. The photoelectric conversion efficiency is smaller than the photoelectric conversion efficiency of the solar cell in the embodiment 1, and the comparative document 3 has a specific hysteresis compared to the embodiment 1.

Comparative Embodiment 4

[0101] A preparation method for organic-inorganic perovskite solar cell is described in the embodiment 2, it is different in step 3, the sulfonamide analogue is introduced, that is: the FAPbI.sub.3 crystal, the MACl, and the 3,4-difluorobenzene sulfonamide are dissolved according to a mole ratio of 1:0.35:0.04, in the mixed solvent of N, N-dimethylformamide and dimethyl sulfoxide (the volume ratio of the N, N-dimethylformamide and dimethyl sulfoxide is 4:1) to obtain the precursor solution, and stirred at the temperature of 40? C. for 4 h, specifically, the concentration of the FAPbI.sub.3 is 1.8 mol/L. Inside a nitrogen-protected glove box, the pipette is used to transfer 70 L of the prepared precursor solution, and the prepared precursor solution is evenly spin-coated on the FTO transparent conductive substrate pretreated in the step 1 by the spin coater; specifically, the speed for spin coating the precursor solution is 6000 rpm, the period for spin coating the precursor solution is 50 s, and 800 ?L of the ether antisolvent is added when the spin coating is performed for 10 s. And after spin coating, the annealing treatment is performed at the temperature of 150? C. for 10 min in the nitrogen atmosphere to prepare and obtain the perovskite film.

[0102] The 3,4-difluorobenzene sulfonamide used in step 3 of the comparative embodiment 4 has a similar functional group with the sulfonamide used in the disclosure, and the 3,4-difluorobenzene sulfonamide is used as a reference in the comparative embodiment 4 to study an effect of the sulfonamide analogue to the perovskite solar cell.

[0103] Other steps and conditions are consistent with the embodiment 2.

[0104] A solar cell prepared in the comparative embodiment 4 in the standard testing condition (lighting with AM 1.5), in a situation of reverse scanning, the photoelectric conversion efficiency is 17.93%, the open current voltage is 1.013 V, the short circuit current is 24.55 mA/cm.sup.2, and a fill factor is 72.10%; in a situation of forward scanning, the photoelectric conversion efficiency is 14.75%, the open current voltage is 0.957 V, the short circuit current is 23.96 mA/cm.sup.2, and the fill factor is 64.33%. The photoelectric conversion efficiency is smaller than the photoelectric conversion efficiency of the solar cell in the embodiment 2, and the comparative document 4 has a serious hysteresis.

[0105] Thus, the 3,4-difluorobenzene sulfonamide is used as an additive introduced to the perovskite film, an improvement of performance is due to passivation of defects by coordination interaction between the functional groups such as S?O and a lead ion (Pb.sup.+) of the perovskite, however, an effect of the 3,4-difluorobenzene sulfonamide to the energy band structure is negligible, an energy level mismatch is not mitigated, which cause the photoelectric conversion efficiency of the device without the electron transport layer is still low, and inefficient carrier transportation causing the serious hysteresis.