Method for manufacturing perovskite particle light-emitter where organic ligand is substituted, particle light-emitter manufactured thereby, and light emitting device using same

Abstract

Provided are a method for manufacturing a perovskite nanocrystal particle light-emitter where an organic ligand is substituted, a light-emitter manufactured thereby, and a light emitting device using the same. A method for manufacturing an organic-inorganic-hybrid perovskite nanocrystal particle light-emitter where an organic ligand is substituted may comprise the steps of: preparing a solution including an organic-inorganic-hybrid perovskite nanocrystal particle light-emitter, wherein the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter comprises an organic-inorganic-hybrid perovskite nanocrystal structure and a plurality of first organic ligands surrounding the organic-inorganic-hybrid perovskite nanocrystal structure; and adding, to the solution, a second organic ligand which is shorter than the first organic ligands or includes a phenyl group or a fluorine group, thereby substitutes the first organic ligands with the second organic ligand. Thus, since energy transfer or charge injection into the nanocrystal structure increases through ligand substitution, it is possible to further increase light emitting efficiency and increase durability and stability by means of a hydrophobic ligand.

Claims

1. A method for manufacturing an inorganic metal halide perovskite nanocrystal particle light-emitter, in which an organic ligand is substituted, the method comprising: preparing a solution comprising the inorganic metal halide perovskite nanocrystal particle light-emitter including an inorganic metal halide perovskite nanocrystal structure and a plurality of first organic ligands surrounding a surface of the inorganic metal halide perovskite nanocrystal structure; and adding a second organic ligand, which has a length less than that of each of the first organic ligands or comprises a phenyl group or fluorine group, to the solution to substitute the first organic ligand with the second organic ligand.

2. The method of claim 1, wherein each of the first organic ligand and the second organic ligand comprises alkyl halide, and a halogen element of the second organic ligand comprises an element having affinity higher than that of a halogen element of the first organic ligand with respect to a center metal of the inorganic metal halide perovskite nanocrystal structure.

3. The method of claim 1, wherein the inorganic metal halide perovskite comprises a structure of ABX.sub.3, A.sub.2BX.sub.4, ABX.sub.4, or A.sub.n−1Pb.sub.nX.sub.3n+1 (where n is an integer between 2 to 6), and the A is an alkali metal, the B is a metal material, and the X is a halogen element.

4. The method of claim 3, wherein the A is Na, K, Rb, Cs, or Fr, the B is a divalent transition metal, a rare earth metal, an alkali earth metal, Pb, Sn, Ge, Ga, In, Al, Sb, Bi, Po, or a combination thereof, and the X is CI, Br, I, or a combination thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic view of a perovskite nanocrystal structure according to an embodiment of the present invention.

(2) FIG. 2 is a flowchart illustrating a method for manufacturing the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter, in which an organic ligand is substituted, according to an embodiment of the present invention.

(3) FIG. 3 is a flowchart illustrating a method for manufacturing the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter according to an embodiment of the present invention.

(4) FIG. 4 is a schematic view illustrating a method for manufacturing the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter according to an embodiment of the present invention.

(5) FIG. 5 is a schematic view of an organic-inorganic-hybrid perovskite nanocrystal particle light-emitter and an inorganic metal halide perovskite nanocrystal particle light-emitter according to an embodiment of the present invention.

(6) FIG. 6 is a schematic view illustrating a method for manufacturing the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter, in which the organic ligand is substituted, according to an embodiment of the present invention.

(7) FIG. 7 is a fluorescent image obtained by photographing emission light by irradiating ultraviolet rays onto a light-emitter according to Manufacturing Example 1, Comparative Example 1, and Comparative Example 2.

(8) FIG. 8 is a schematic view of a light-emitter according to Manufacturing Example 1 and Comparative Example 1.

(9) FIG. 9 is an image obtained by photographing a photoluminescence matrix of the light-emitter at room temperature and a low temperature according to Manufacturing Example 30 and Comparative Example 1.

(10) FIG. 10 is a graph obtained by photographing photoluminescence of the light-emitter according to Manufacturing Example 1 and Comparative Example 1.

(11) FIG. 11 is a schematic view of the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter, in which the organic ligand is substituted, according to an embodiment of the present invention.

MODE FOR CARRYING OUT THE INVENTION

(12) Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(13) It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

(14) In the following description, it will be understood that when an element such as a layer, a region, or substrate is referred to as being ‘on’ another layer, region, or substrate, it can be directly on the other layer, region, or substrate, or intervening layers, regions, or substrates may also be present.

(15) Although the terms such as “first,” “second,” etc., are used to describe various element, components, regions, layers, and/or portions, it is obvious that the elements, components, regions, layers, and/or portions should not be defined by these terms.

(16) FIG. 1 is a schematic view of a perovskite nanocrystal structure according to an embodiment of the present invention.

(17) FIG. 1 illustrates structures of an organic-inorganic-hybrid perovskite nanocrystal and an inorganic metal halide perovskite nanocrystal.

(18) Referring to FIG. 1, the organic-inorganic-hybrid perovskite nanocrystal has a structure with a center metal centered in a face centered cubic (FCC), in which six inorganic halide materials X are respectively located on all surfaces of a hexahedron, and in a body centered cubic (BCC), in which eight organic ammonium OA are respectively located at ail vertexes of a hexahedron. Here, Pb is illustrated as an example of the center metal.

(19) Also, the inorganic metal halide perovskite nanocrystal has structure with a center metal centered in a face centered cubic (FCC), in which six inorganic halide materials X are respectively located on all surfaces of a hexahedron, and in a body centered cubic (BCC), in which eight alkali metals are respectively located at all vertexes of a hexahedron. Here, Pb is illustrated as an example of the center metal.

(20) Here, all sides of the hexahedron have an angle of 90° with respect to each other. The above-described structure may include a cubic structure having the same length in horizontal, vertical, and height directions and a tetragonal structure having different lengths in the horizontal, vertical, and height directions.

(21) Thus, a two-dimensional (2D) structure according to the present invention may be the organic-inorganic-hybrid perovskite nanocrystal structure with a center metal centered in a face centered cubic, in which six inorganic halide materials X are respectively located on all surfaces of a hexahedron, and in a body centered cubic, in which eight organic ammonium are respectively located at all vertexes of a hexahedron and be defined as a structure of which a horizontal length and a vertical length are the same, but a height length is longer by 1.5 times or more than each of the horizontal length and the vertical length.

(22) A method for manufacturing the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter, in which the organic ligand is substituted, according to an embodiment of the present invention will be described.

(23) FIG. 2 is a flowchart illustrating a method for manufacturing the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter, in which an organic ligand is substituted, according to an embodiment of the present invention.

(24) Referring to FIG. 2, the method for manufacturing the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter, in which an organic ligand is substituted, includes a step (S100) of preparing a solution including an organic-inorganic-hybrid perovskite nanocrystal light-emitter and a step (S200) of substituting a first organic ligand of the organic-inorganic-hybrid perovskite nanocrystal light-emitter with a second organic ligand in the solution.

(25) In more detail, first, a solution including an organic-inorganic-hybrid perovskite nanocrystal light-emitter is prepared (S100). The organic-inorganic-hybrid perovskite nanocrystal light-emitter may include a plurality of first organic ligands surrounding an organic-inorganic-hybrid or metal halide perovskite nanocrystal structure and the organic-inorganic-hybrid perovskite nanocrystal structure.

(26) The step of preparing the solution including the organic-inorganic-hybrid perovskite nanocrystal light-emitter may be a step of manufacturing and preparing the organic-inorganic-hybrid perovskite nanocrystal light-emitter. One manufacturing example will be described with reference to FIGS. 3 to 5.

(27) FIG. 3 is a flowchart illustrating a method for manufacturing the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter according to an embodiment of the present invention.

(28) Referring to FIG. 3, the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter according to the present invention may be manufactured through an inverse nano-emulsion method, reprecipitation method, or hot injection method.

(29) First, the first solution in which the organic-inorganic-hybrid perovskite is dissolved in a polar solvent and the second solution in which a surfactant is dissolved in a non-polar solvent are prepared (S110).

(30) Here, the polar (aprotic or protic) solvent may include dimethylformamide, gamma butyrolactone, N-methylpyrrolidone, dimethylsulfoxide or isopropyl alcohol, but is not limited thereto.

(31) Also, the organic-inorganic-hybrid perovskite may be a material having a 2D crystalline structure, a 3D crystalline structure or a combination thereof.

(32) For example, the organic-inorganic-hybrid perovskite having the 3D crystal structure may be an ABX.sub.3 structure. Also, the organic-inorganic-hybrid perovskite having the 2D crystal structure may be a structure of ABX.sub.3, A.sub.2BX.sub.4, ABX.sub.4, or A.sub.n−1Pb.sub.nX.sub.3n+1 (where n is an integer between 2 to 6).

(33) Here, the A is an organic ammonium or inorganic alkali metal material, the B is a metal material, and the X is a halogen element.

(34) For example, the A may be (CH.sub.3NH.sub.3).sub.n, ((C.sub.xH.sub.2x+1).sub.nNH.sub.3).sub.2(CH.sub.3NH.sub.3).sub.n, (RNH.sub.3).sub.2, (C.sub.nH.sub.2n+1NH.sub.3).sub.2, CF.sub.3NH.sub.3, (CF.sub.3NH.sub.3).sub.n, ((C.sub.xF.sub.2x+1).sub.nNH.sub.3).sub.2(CF.sub.3NH.sub.3).sub.n, ((C.sub.xCF.sub.2x+1).sub.nNH.sub.3).sub.2, (C.sub.nF.sub.2n+1NH.sub.3).sub.2, (CH(NH.sub.2).sub.2), C.sub.xH.sub.2x+1(C(NH.sub.2).sub.2), Cs, Rb, K, (where n is an integer equal to or greater than 1, and x is an integer equal to or greater than 1). Here, the B may be a divalent transition metal, a rare earth metal, an alkali earth metal, Pb, Sn, Ge, Ga, In, Al, Sb, Bi, Po, or a combination thereof. Here, the rare earth metal may be, for example, Ge, Sn, Pb, Eu, or Yb. Also, the alkali earth metal may be, for example, Ca or Sr. Also, the X may be Cl, Br, I, or a combination thereof.

(35) The perovskite may be prepared by combining the AX with BX.sub.2 at a predetermined ratio. That is, the first solution may be formed by dissolving the AX and BX.sub.2 in the polar solvent at a predetermined ratio. For example, the AX and BX.sub.2 may be dissolved in the polar solvent at a ratio of 2:1 to prepare the first solution in which the A.sub.2BX.sub.3 organic-inorganic-hybrid perovskite is dissolved.

(36) Also, it is preferable that the organic-inorganic-hybrid perovskite uses a material having a 2D crystal structure rather than a 2D crystal structure.

(37) When the organic-inorganic-hybrid perovskite having the 2D structure is formed to have the nanocrystal in comparison that the organic-inorganic-hybrid perovskite having the 3D structure is formed to have the nanocrystal, the inorganic plane and the organic plane, which are stacked on each other, may be clearly distinguished from each other to more firmly confine the exciton in the inorganic plane with respect to the organic plane and thereby to improve luminescent efficiency and durability (or stability), thereby implementing higher color purity.

(38) Also, the non-polar solvent may include dichloroethylene, trichlorethylene, chloroform, chlorobenzene, dichlorobenzene, styrene, xylene, toluene, or cyclohexene, but is not limited thereto.

(39) Also, the alkyl halide surfactant may have a structure of alkyl-X. Here, the halogen element corresponding to the X may include Cl, Br, or I. Also, the alkyl structure may include acyclic alkyl having a structure of C.sub.nH.sub.2n+1, primary alcohol having a structure such as C.sub.nH.sub.2n+1OH, secondary alcohol, tertiary alcohol, alkylamine having a structure of alkyl-N (e.g., hexadecyl amine, 9-Octadecenylamine 1-Amino-9-octadecene (C.sub.19H.sub.37N)), p-substituted aniline, phenyl ammonium, or fluorine ammonium, but is not limited thereto.

(40) A carboxylic acid (COOH) and amines (NH.sub.3) surfactant may be used instead of the alkyl halide surfactant.

(41) For example, the surfactant may include a carboxylic acid such as a 4,4′-Azobis(4-cyanovaleric acid), an acetic acid, a 5-aminosalicylic acid, an acrylic acid, an L-aspentic acid, a 6-bromohexanoic acid, a bromoacetic acid, a dichloro acetic acid, an ethylenediaminetetraacetic acid, an isobutyric acid, an itaconic acid, a maleic acid, an r-maleimidobutyric acid, an L-malic acid, a 4-Nitrobenzoic acid, a 1-pyrenecarboxylic acid, or an oleic acid, but is not limited thereto.

(42) Next, the first solution may be mixed with the second solution to form the nanocrystal particle. (S200).

(43) In the step of mixing the first solution with the second solution to form the nanocrystal particle, it is preferable to mix the first solution by dropping into the second solution in drops. Also, the second solution may be stirred. For example, the second solution in which the organic-inorganic-hybrid perovskite (OIP) is dissolved may be slowly added dropwise into the second solution in which the alkyl halide surfactant that is being strongly stirred is dissolved to synthesize the nanocrystal particle.

(44) In this case, when the first solution drops to be mixed with the second solution, the organic-inorganic-hybrid perovskite (OIP) is precipitated from the second solution due to a difference in solubility. Also, a surface of the organic-inorganic-hybrid perovskite (OIP) precipitated from the second solution is surrounded by the alkyl halide surfactant and thus stabilized to generate an organic-inorganic-hybrid perovskite nanocrystal (OIP-NC) that is well dispersed. Thus, the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter including the organic-inorganic-hybrid perovskite nanocrystal structure and the plurality of alkyl halide organic ligands or inorganic binary compounds or combination thereof surrounding the organic-inorganic-hybrid perovskite nanocrystal structure may be manufactured.

(45) The organic-inorganic-hybrid perovskite nanocrystal particle may have a size that is controllable by adjusting a length or a shape factor of the alkyl halide surfactant. For example, the adjustment of the shape factor may be controlled through the surfactant having a linear, tapered, or inverted triangular shape.

(46) It is preferable that the generated organic-inorganic-hybrid perovskite nanocrystal particle has a size of 1 nm to 900 nm. Here, the size of the nanocrystal particle represents a size without considering a size of the ligand that will be described later, i.e., a size of a remaining portion except for the ligand.

(47) If the organic-inorganic-hybrid perovskite nanocrystal particle has a size exceeding 900 nm, it is a fundamental problem in which the large non-radiative decay of the excitons can occur at room temperature by thermal ionization and the delocalization of the charge carrier, and a large number of excitons are separated as free charge carriers and then annihilated.

(48) FIG. 4 is a schematic view illustrating a method for manufacturing the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter having the 2D structure according to an embodiment of the present invention.

(49) Referring to FIG. 4(a), the first solution in which the organic-inorganic-hybrid perovskite is dissolved in the polar solvent is added dropwise into the second solution in which the alkyl halide surfactant is dissolved in the non-polar solvent.

(50) Referring to FIG. 4(b), when the first solution is added to the second solution, the organic-inorganic-hybrid perovskite is precipitated from the second solution due to a difference in solubility. A surface of the precipitated organic-inorganic-hybrid perovskite is surrounded by the alkyl halide surfactant and thus stabilized to generate an organic-inorganic-hybrid perovskite nanocrystal particle light-emitter 100 that is well dispersed. Here, the surface of the organic-inorganic-hybrid perovskite nanocrystal structure is surrounded by the organic ligands that include alkyl halide, inorganic binary compounds or combination thereof.

(51) Thereafter, the polar solvent including the organic-inorganic-hybrid perovskite nanocrystal particle that is dispersed in the non-polar solvent, in which the alkyl halide surfactant is dissolved, may be heated and thus selectively evaporated, or a co-solvent, in which all the polar and non-polar solvents are capable of being dissolved, may be added to selectively extract the polar solvent including the nanocrystal particle from the non-polar solvent, thereby obtaining the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter.

(52) The organic-inorganic-hybrid perovskite nanocrystal particle light-emitter having the 2D structure according to an embodiment of the present invention will be described.

(53) The organic-inorganic-hybrid perovskite nanocrystal particle light-emitter according to an embodiment of the present invention may include an organic-inorganic-hybrid perovskite nanocrystal structure that has the 2D structure and is dispersible in an organic solvent. Here, the organic solvent may be the polar solvent or the non-polar solvent. For example, the polar solvent may include dimethylformamide, gamma butyrolactone, N-methylpyrrolidone, dimethylsulfoxide or isopropyl alcohol, and the non-polar solvent may include dichloroethylene, trichlorethylene, chloroform, chlorobenzene, dichlorobenzene, styrene, dimethylformamide, dimethylsulfoxide, xylene, toluene, cyclohexene.

(54) Also, the nanocrystal particle may have a spherical, cylindrical, cylindroid, polyprism or two-dimensional (lamellar, plate) shape.

(55) Also, the nanocrystal particle may have a size of 1 nm to 900 nm. Here, the size of the nanocrystal particle represents a size without considering a size of the ligand that will be described later, i.e., a size of a remaining portion except for the ligand. For example, when the nanocrystal particle has the spherical shape, the nanocrystal particle may have a diameter of 1 nm to 900 nm.

(56) Also, the nanocrystal particle may have bandgap energy of 1 eV to 5 eV. Thus, since the energy bandgap is determined according to the composition and the crystal structure of the nanocrystal particle, the composition of the nanocrystal particle may be adjusted to emit light having a wavelength of, for example, 200 nm to 1300 nm.

(57) Also, the plurality of organic ligands surrounding the organic-inorganic-hybrid perovskite nanocrystal structure may be further provided.

(58) Hereinafter, embodiments of the present invention will be described with reference to FIG. 5.

(59) FIG. 5 is a schematic view of an organic-inorganic-hybrid perovskite nanocrystal particle light-emitter and an inorganic metal halide perovskite nanocrystal particle light-emitter according to an embodiment of the present invention.

(60) Here, FIG. 5 illustrates the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter. If the organic-inorganic-hybrid perovskite of FIG. 5 is changed into the inorganic metal halide perovskite, since the inorganic metal halide perovskite nanocrystal particle light-emitter is provided, their descriptions are the same.

(61) Referring to FIG. 5, the light-emitter according to an embodiment of the present invention may be the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter or the inorganic metal halide perovskite nanocrystal particle light-emitter and includes an organic-inorganic-hybrid perovskite nanocrystal structure or inorganic metal halide perovskite nanocrystal structure 110 that is dispersible in the organic solvent.

(62) Also, the organic-inorganic-hybrid perovskite having the 2D crystal structure may be a structure of A.sub.2BX.sub.4, ABX.sub.4, or A.sub.n+1Pb.sub.nX.sub.3n+1 (where, n is an integer between 2 to 6).

(63) Here, the A is an organic ammonium or inorganic alkali metal material, the B is a metal material, and the X is a halogen element. For example, the A may be (CH.sub.3NH.sub.3).sub.n, ((C.sub.xH.sub.2x+1).sub.nNH.sub.3).sub.2(CH.sub.3NH.sub.3).sub.n, (RNH.sub.3).sub.2, (C.sub.nH.sub.2n+1NH.sub.3).sub.2, CF.sub.3NH.sub.3, (CF.sub.3NH.sub.3).sub.n, ((C.sub.xF.sub.2x+1).sub.nNH.sub.3).sub.2 (CF.sub.3NH.sub.3).sub.n, ((C.sub.xCF.sub.2x+1).sub.nNH.sub.3).sub.2, (C.sub.nF.sub.2n+1NH.sub.3).sub.2, (CH(NH.sub.2).sub.2), C.sub.xH.sub.2x+1(C(NH.sub.2).sub.2), Cs, Rb, K, (where n is an integer equal to or greater than 1, and x is an integer equal to or greater than 1). Here, the B may be a divalent transition metal, a rare earth metal, an alkali earth metal, Pb, Sn, Ge, Ga, In, Al, Sb, Bi, Po, or a combination thereof. Here, the rare earth metal may be, for example, Ge, Sn, Pb, Eu, or Yb. Also, the alkali earth metal may be, for example, Ca or Sr. Also, the X may be Cl, Br, I, or a combination thereof.

(64) The organic-inorganic-hybrid perovskite nanocrystal particle light-emitter 100 having the 2D structure according to the present invention may further include a plurality of organic ligands 120 or combination thereof surrounding the above-described organic-inorganic-hybrid or metal halide perovskite nanocrystal structure 110. Each of the organic ligands 120 may include alkyl halide.

(65) Also, the alkyl halide surfactant may have a structure of alkyl-X. Here, the halogen element corresponding to the X may include Cl, Br, or I. Also, the alkyl structure may include acyclic alkyl having a structure of C.sub.nH.sub.2n+1, primary alcohol having a structure such as C.sub.nH.sub.2n+1OH, secondary alcohol, tertiary alcohol, alkylamine having a structure of alkyl-N (e.g., hexadecyl amine, 9-Octadecenylamine 1-Amino-9-octadecene (C.sub.19H.sub.37N)), p-substituted aniline, phenyl ammonium, or fluorine ammonium, but is not limited thereto.

(66) Also, the inorganic metal halide perovskite having the 2D crystal structure may be a structure of A.sub.2BX.sub.4, ABX.sub.4, or A.sub.n−1Pb.sub.nX.sub.3n+1 (where, n is an integer between 2 to 6).

(67) The A may be an alkali metal, the B may be a divalent transition metal, a rare earth metal, an alkali earth metal, Pb, Sn, Ge, Ga, In, Al, Sb, Bi, Po, or a combination thereof, and the X may be Cl, Br, I, or a combination thereof. Here, the rare earth metal may be, for example, Ge, Sn, Pb, Eu, or Yb. Also, the alkali earth metal may be, for example, Ca or Sr.

(68) The inorganic metal halide perovskite nanocrystal particle light-emitter having the 2D structure according to the present invention may further include a plurality of organic ligands surrounding the above-described inorganic metal halide perovskite nanocrystal structure. Each of the organic ligands may include alkyl halide.

(69) Referring again to FIG. 2, a first organic ligand of the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter is substituted with a second organic ligand in the solution (S200).

(70) Here, the second organic ligand having a length less than that of the first organic ligand or including a phenyl group or a fluorine group may be added to the solution to substitute the first organic ligand with the second organic ligand. Here, heat may be applied to perform substitution reaction.

(71) Each of the second organic ligands may include alkyl halide. Also, the second organic ligand may have a structure of alkyl-X′. Here, the halogen element corresponding to the X′ may include Cl, Br, or I. Also, the alkyl structure may include acyclic alkyl having a structure of C.sub.nH.sub.2n+1, primary alcohol having a structure such as C.sub.nH.sub.2n+1OH, secondary alcohol, tertiary alcohol, alkylamine having a structure of alkyl-N (e.g., hexadecyl amine, 9-Octadecenylamine 1-Amino-9-octadecene (C.sub.19H.sub.37N)), p-substituted aniline, phenyl ammonium, or fluorine ammonium, but is not limited thereto.

(72) Also, the second organic ligand may include alkyl halide, and the halogen element of the second organic ligand may be an element having a higher affinity for a center metal of the organic-inorganic-hybrid perovskite nanocrystal structure than that of the halogen element of the first organic ligand.

(73) For example, when the first organic ligand is CH.sub.3(CH.sub.2).sub.17NH.sub.3Br, CH.sub.3(CH.sub.2).sub.8NH.sub.3I as an alkali halide surfactant having a short length and including the halogen element that has a higher affinity for a center metal of the organic-inorganic-hybrid perovskite nanocrystal structure than that of the halogen element of the first organic ligand may be added and then heated to perform the organic ligand substitution. Thus, CH.sub.3(CH.sub.2).sub.8NH.sub.3I may become the second organic ligand surrounding the nanocrystal structure, and thus, the organic ligand of the nanocrystal particle light-emitter may be reduced in length.

(74) As described above, in the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter according to the present invention, the alkyl halide (the first organic ligand) used as the surfactant for stabilizing the surface of the precipitated organic-inorganic-hybrid perovskite may surround the surface of the organic-inorganic-hybrid perovskite to form the nanocrystal structure.

(75) If the alkyl halide surfactant has a short length, the formed nanocrystal particle may increase in size to exceed 900 nm. In this case, the light emission of the exciton may not occur by thermal ionization and the delocalization of the charge carriers in the large nanocrystal particle, and the exciton may be separated as the free charge carriers and then annihilated.

(76) That is, the size of the formed organic-inorganic-hybrid perovskite nanocrystal particle is inversely proportional to the length of the alkyl halide surfactant used for forming the nanocrystal particle.

(77) Thus, the size of the organic-inorganic-hybrid perovskite nanocrystal particle formed by using the alkyl halide having a predetermined length or more as the surfactant may be controlled to a predetermined size or less. For example, octadecyl-ammonium bromide may be used as the alkyl halide surfactant to form the organic-inorganic-hybrid perovskite nanocrystal particle having a size of a 900 nm or less.

(78) Thus, the alkyl halide (the first organic ligand) having a predetermined length or more may be used to form the nanocrystal particle having a predetermined size or more, and then, the first organic ligand may be substituted with the ligand having the short length or including the phenyl group or the fluorine group to more increase the energy transfer or the charge injection in the nanocrystal structure, thereby more improving the luminescent efficiency. Furthermore, durability (or stability) may also be improved by the substituted hydrophobic ligand.

(79) The substitution step (S200) will be described in more detail with reference to FIG. 6.

(80) FIG. 6 is a schematic view illustrating a method for manufacturing the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter, in which the organic ligand is substituted, according to an embodiment of the present invention.

(81) Referring to FIG. 6(a), the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter 100 including the organic-inorganic-hybrid perovskite nanocrystal structure 110 and the first organic ligand 120 surrounding the nanocrystal structure 110 is prepared. The nanocrystal particle light-emitter 100 may be prepared in state (a liquid state) that is contained in a solution. As illustrated in the drawings, Pb may be described as an example of the center metal of the organic-inorganic-hybrid perovskite nanocrystal structure 110.

(82) Next, the second organic ligand 130 is added to the solution containing the nanocrystal particle light-emitter 100.

(83) Referring to FIG. 6(b), since the second organic ligand 130 is added, the first organic ligand 120 is substituted with the second organic ligand 130. The organic ligand substitution may be performed by using an intensity difference in affinity between the center metal of the organic-inorganic-hybrid perovskite nanocrystal structure 110 and the halogen element. For example, the affinity with the center metal may increase in order of Cl<Br<I.

(84) Thus, when the halogen element X of the first organic ligand 120 is Cl, the ligand substitution may be performed by using Br or I as the halogen element X′ of the second organic ligand 130.

(85) Thus, the first organic ligand 120 may be substituted with the second organic ligand 130 having the short length and including the fluorine group to form an organic-inorganic-hybrid perovskite nanocrystal particle light-emitter 100′ which has improved luminescent efficiency and in which the organic ligand is substituted.

(86) A method for manufacturing the inorganic metal halide perovskite nanocrystal particle light-emitter, in which the organic ligand is substituted, according to an embodiment of the present invention will be described.

(87) The method for manufacturing the inorganic metal halide perovskite nanocrystal particle light-emitter, in which the organic ligand is substituted may include a step of preparing a solution including an inorganic metal halide perovskite nanocrystal particle light-emitter including an inorganic metal halide perovskite nanocrystal structure and a plurality of first organic ligands surrounding a surface of the inorganic metal halide perovskite nanocrystal structure and a step of adding a second organic ligand having a short length or including a phenyl group or a fluorine group to substitute the first organic ligand with the second organic ligand.

(88) Each of the first organic ligand and the second organic ligand may include alkyl halide, and the halogen element of the second organic ligand may be an element having affinity higher than that of the halogen element of the first organic ligand with respect to a center metal of the organic-inorganic-hybrid perovskite nanocrystal structure.

(89) The inorganic metal halide perovskite material may include a structure of ABX.sub.3, A.sub.2BX.sub.4, ABX.sub.4, or A.sub.n−1Pb.sub.nX.sub.3n+1 (n is an integer between 2 to 6), where the A may be an alkali metal, the B may be a metal material, and the X may be a halogen element.

(90) Here, the A may be Na, K, Rb, Cs, or Fr, the B may be a divalent transition metal, a rare earth metal, an alkali earth metal, Pb, Sn, Ge, Ga, In, Al, Sb, Bi, Po, or a combination thereof, and the X may be Cl, Br, I, or a combination thereof.

(91) Here, the substitution methods may be the same except that, in the “inorganic metal halide” perovskite nanocrystal particle, an A side material is an alkali metal, and in the “organic-inorganic-hybrid” perovskite nanocrystal particle, an A site material is an organic ammonium material. Thus, the method for substituting the organic ligand of the inorganic metal halide perovskite nanocrystal particle is the same as that for manufacturing the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter in which the organic ligand is substituted, and thus, its detailed description will be omitted.

(92) A light emitting device according to an embodiment of the present invention will be described.

(93) A light emitting device according to an embodiment of the present invention may be a device using a light emitting layer including an organic-inorganic-hybrid perovskite nanocrystal light-emitter in which an organic ligand is substituted or an inorganic metal halide perovskite nanocrystal particle light-emitter in which an organic ligand is substituted. Here, the organic-inorganic-hybrid perovskite nanocrystal light-emitter in which the organic ligand is substituted or the inorganic metal halide perovskite nanocrystal particle light-emitter in which the organic ligand is substituted may be manufactured through the above-described manufacturing methods.

(94) For example, the light emitting device according to the present invention may include a first electrode, a second electrode, and a light emitting layer disposed between the first electrode and the second electrode and including the organic-inorganic-hybrid perovskite nanocrystal light-emitter in which the organic ligand is substituted or the inorganic metal halide perovskite nanocrystal particle light-emitter in which the organic ligand is substituted.

(95) For another example, the organic-inorganic-hybrid perovskite nanocrystal particle in which the organic ligand is substituted or the inorganic metal halide perovskite nanocrystal particle in which the organic ligand is substituted may be applied to a solar cell by using a photoactive layer including the above-described organic-inorganic-hybrid perovskite nanocrystal particle and the inorganic metal halide perovskite nanocrystal particle. The solar cell may include a first electrode, a second electrode, and a photoactive layer disposed between the first electrode and the second electrode and including the above-described perovskite nanocrystal particle.

Manufacturing Example 1

(96) An organic-inorganic-hybrid perovskite nanocrystal colloidal particle light-emitter having a 3D structure according to an embodiment of the present invention was formed. The inorganic metal halide perovskite nanocrystal colloidal particle light-emitter was formed through an inverse nano-emulsion method, or reprecipitation method, or hot injection method.

(97) Particularly, organic-inorganic-hybrid perovskite was dissolved in a polar solvent to prepare a first solution. Here, dimethylformamide was used as the polar solvent, and CH.sub.3NH.sub.3PbBr.sub.3 was used as the organic-inorganic-hybrid perovskite. Here, the used CH.sub.3NH.sub.3PbBr.sub.3 was prepared by mixing CH.sub.3NH.sub.3Br with PbBr.sub.2 at a ratio of 1:1.

(98) Also, a second solution in which an alkyl halide surfactant is dissolved in a non-polar solvent was prepared. Here, toluene was used as the non-polar solvent, and octadecylammonium bromide (CH.sub.3(CH.sub.2).sub.17NH.sub.3Br) was used as the alkyl halide surfactant.

(99) Then, the first solution slowly dropped drop wise into the second solution that is being strongly stirred to form the organic-inorganic-hybrid perovskite nanocrystal colloidal particle light-emitter having the 3D structure.

(100) Then, the organic-inorganic-hybrid perovskite colloidal nanocrystal particle that is in a liquid state was spin-coated on a glass substrate to form an organic-inorganic-hybrid perovskite nanocrystal particle thin film (OIP-NP film).

(101) Here, the formed organic-inorganic-hybrid perovskite nanocrystal particle has a size of about 20 nm.

Manufacturing Example 2

(102) The same process as that according to Manufacturing Example 1 was performed, and CH.sub.3 (CH.sub.2).sub.13NH.sub.3Br was used as an alkyl halide surfactant to form an organic-inorganic-hybrid perovskite nanocrystal colloidal particle light-emitter having a 3D structure according to an embodiment of the present invention.

(103) Here, the formed organic-inorganic-hybrid perovskite nanocrystal particle has a size of about 100 nm.

Manufacturing Example 3

(104) The same process as that according to Manufacturing Example 1 was performed, and CH.sub.3 (CH.sub.2).sub.10NH.sub.3Br was used as an alkyl halide surfactant to form an organic-inorganic-hybrid perovskite nanocrystal particle light-emitter having a 3D structure according to an embodiment of the present invention.

(105) Here, the formed organic-inorganic-hybrid perovskite nanocrystal particle has a size of about 300 nm.

Manufacturing Example 4

(106) The same process as that according to Manufacturing Example 1 was performed, and CH.sub.3(CH.sub.2).sub.7NH.sub.3Br was used as an alkyl halide surfactant to form an organic-inorganic-hybrid perovskite nanocrystal particle light-emitter having a 3D structure according to an embodiment of the present invention.

(107) Here, the formed organic-inorganic-hybrid perovskite nanocrystal particle has a size of about 500 nm.

Manufacturing Example 5

(108) The same process as that according to Manufacturing Example 1 was performed, and CH.sub.3(CH.sub.2).sub.4NH.sub.3Br was used as an alkyl halide surfactant to form an organic-inorganic-hybrid perovskite nanocrystal particle light-emitter having a 3D structure according to an embodiment of the present invention.

(109) Here, the formed organic-inorganic-hybrid perovskite nanocrystal particle has a size of about 700 nm.

Manufacturing Example 6

(110) The same process as that according to Manufacturing Example 1 was performed, and CH.sub.3CH.sub.2NH.sub.3Br was used as an alkyl halide surfactant to form an organic-inorganic-hybrid perovskite nanocrystal particle light-emitter having a 3D structure according to an embodiment of the present invention.

(111) Here, the formed organic-inorganic-hybrid perovskite nanocrystal particle has a size of about 800 nm.

Manufacturing Example 7

(112) The same process as that according to Manufacturing Example 1 was performed, and CH.sub.3NH.sub.3Br was used as an alkyl halide surfactant to form an organic-inorganic-hybrid perovskite nanocrystal particle light-emitter having a 3D structure according to an embodiment of the present invention.

(113) Here, the formed organic-inorganic-hybrid perovskite nanocrystal particle has a size of about 900 nm.

Manufacturing Example 8

(114) An organic-inorganic-hybrid perovskite nanocrystal particle light-emitter having a 3D structure according to an embodiment of the present invention was formed. The inorganic metal halide perovskite nanocrystal particle light-emitter was formed through an inverse nano-emulsion method, or reprecipitation method, or hot injection method.

(115) Particularly, organic-inorganic-hybrid perovskite was dissolved in a polar solvent to prepare a first solution. Here, dimethylformamide was used as the polar solvent, and (CH.sub.3NH.sub.3).sub.2PbBr.sub.3 was used as the organic-inorganic-hybrid perovskite. Here, the used CH.sub.3NH.sub.3PbBr.sub.3 was prepared by mixing CH.sub.3NH.sub.3Br with PbBr.sub.2 at a ratio of 1:1.

(116) Also, a second solution in which an alkyl halide surfactant is dissolved in a non-polar solvent was prepared. Here, toluene was used as the non-polar solvent, and octadecylammonium bromide (CH.sub.3(CH.sub.2).sub.17NH.sub.3Br) was used as the alkyl halide surfactant.

(117) Then, the first solution slowly dropped drop wise into the second solution that is being strongly stirred to form an organic-inorganic-hybrid perovskite nanocrystal particle light-emitter having a 2D structure. Here, the formed organic-inorganic-hybrid perovskite nanocrystal particle has a size of about 20 nm.

(118) Then, CH.sub.3(CH.sub.2).sub.8NH.sub.3I as an alkyl halide surfactant may be added to the second solution and heated to perform the organic ligand substitution. Thus, CH.sub.3(CH.sub.2).sub.8NH.sub.3I may become the second organic ligand surrounding the nanocrystal structure. Thus, the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter, in which the organic ligand is substituted, including the organic-inorganic-hybrid perovskite nanocrystal structure having a size of about 20 nm and the CH.sub.3(CH.sub.2).sub.8NH.sub.3I organic ligand surrounding the nanocrystal structure was manufactured.

Manufacturing Example 9

(119) The same process as that according to Manufacturing Example 1 was performed, and (CH.sub.3NH.sub.3).sub.2PbCl.sub.4 was used as the organic-inorganic-hybrid perovskite. Here, the used (CH.sub.2NH.sub.2).sub.2PbCl.sub.4 was prepared by mixing CH.sub.3NH.sub.3Cl with PbCl.sub.2 at a ratio of 2:1.

(120) Here, the formed organic-inorganic-hybrid perovskite nanocrystalline particle emits light near to ultraviolet or blue color. The light emission spectrum is located at about 380 nm.

Manufacturing Example 10

(121) The same process as that according to Manufacturing Example 1 was performed, and (CH.sub.3NH.sub.3).sub.2PbCl.sub.4 was used as the organic-inorganic-hybrid perovskite. Here, the used (CH.sub.3NH.sub.3).sub.2PbCl.sub.4 was prepared by mixing CH.sub.3NH.sub.3Cl with PbCl.sub.2 at a ratio of 2:1.

(122) Here, the formed organic-inorganic-hybrid perovskite nanocrystalline particle emits light near to infrared or red color. The light emission spectrum is located at about 780 nm.

Manufacturing Example 11

(123) The same process as that according to Manufacturing Example 1 was performed, and (CH.sub.3NH.sub.3).sub.2PbCl.sub.xBr.sub.4−x was used as the organic-inorganic-hybrid perovskite. Here, the used (CH.sub.3NH.sub.3).sub.2PbCl.sub.xBr.sub.4−x was prepared by mixing CH.sub.3NH.sub.3Cl with PbBr.sub.2 at a ratio of 2:1.

(124) Here, the light emission spectrum of the formed organic-inorganic-hybrid perovskite nanocrystalline particle is located between 380 nm and 520 nm.

Manufacturing Example 12

(125) The same process as that according to Manufacturing Example 1 was performed, and (CH.sub.3NH.sub.3).sub.2PbI.sub.xBr.sub.4−x was used as the organic-inorganic-hybrid perovskite. Here, the used (CH.sub.3NH.sub.3).sub.2PbI.sub.xBr.sub.4−x was prepared by mixing CH.sub.3NH.sub.3I with PbBr.sub.2 at a predetermined ratio.

(126) Here, the light emission spectrum of the formed organic-inorganic-hybrid perovskite nanocrystalline particle is located between 520 nm and 780 nm.

Manufacturing Example 13

(127) The same process as that according to Manufacturing Example 1 was performed, and (CH(NH.sub.2).sub.2).sub.2PbI.sub.4 was used as the organic-inorganic-hybrid perovskite. Here, the used (CH(NH.sub.2).sub.2).sub.2PbI.sub.4 was prepared by mixing CH(NH.sub.2).sub.2I with PbI.sub.2 at a ratio of 2:1.

(128) Here, the light emission spectrum of the formed organic-inorganic-hybrid perovskite nanocrystalline particle emits infrared light and is located at about 800 nm.

Manufacturing Example 14

(129) The same process as that according to Manufacturing Example 1 was performed, and (CH.sub.3NH.sub.3).sub.2Pb.sub.xSn.sub.1−xI.sub.4 was used as the organic-inorganic-hybrid perovskite. Here, the used (CH.sub.3NH.sub.3).sub.2Pb.sub.xSn.sub.1−xI.sub.4 was prepared by mixing CH.sub.3NH.sub.3I with PbxSn.sub.1−xI.sub.2 at a ratio of 2:1.

(130) Here, the light emission spectrum of the formed organic-inorganic-hybrid perovskite nanocrystalline particle is located between 820 nm and 1120 nm.

Manufacturing Example 15

(131) The same process as that according to Manufacturing Example 1 was performed, and (CH.sub.2NH.sub.3).sub.2Pb.sub.xSn.sub.1−xBr.sub.4 was used as the organic-inorganic-hybrid perovskite. Here, the used (CH.sub.3NH.sub.3).sub.2Pb.sub.xSn.sub.1−xBr.sub.4 was prepared by mixing CH.sub.3NH.sub.2Br with Pb.sub.xSn.sub.1−xBr.sub.2 at a ratio of 2:1.

(132) Here, the light emission spectrum of the formed organic-inorganic-hybrid perovskite nanocrystalline particle is located between 540 nm and 650 nm.

Manufacturing Example 16

(133) The same process as that according to Manufacturing Example 1 was performed, and (CH.sub.3NH.sub.3).sub.2Pb.sub.xSn.sub.1−xCl.sub.4 was used as the organic-inorganic-hybrid perovskite. Here, the used (CH.sub.3NH.sub.3).sub.2Pb.sub.xSn.sub.1−xCl.sub.4 was prepared by mixing CH.sub.3NH.sub.3Cl with Pb.sub.xSn.sub.1−xCl.sub.2 at a ratio of 2:1.

(134) Here, the light emission spectrum of the formed organic-inorganic-hybrid perovskite nanocrystalline particle is located between 400 nm and 460 nm.

Manufacturing Example 17

(135) The same process as that according to Manufacturing Example 1 was performed, and (C.sub.4H.sub.9NH.sub.3)PbBr.sub.4 was used as the organic-inorganic-hybrid perovskite. Here, the used (C.sub.4H.sub.9NH.sub.3)PbBr.sub.4 was prepared by mixing (C.sub.4H.sub.9NH.sub.3)Br with PbBr.sub.2 at a ratio of 2:1.

(136) Here, the light emission spectrum of the formed organic-inorganic-hybrid perovskite nanocrystalline particle is located at about 411 nm.

Manufacturing Example 18

(137) The same process as that according to Manufacturing Example 1 was performed, and (C.sub.5H.sub.11NH.sub.3)PbBr.sub.4 was used as the organic-inorganic-hybrid perovskite. Here, the used (C.sub.5H.sub.11NH.sub.3)PbBr.sub.4 was prepared by mixing (C.sub.5H.sub.11NH.sub.3)Br with PbBr.sub.2 at a ratio of 2:1.

(138) Here, the light emission spectrum of the formed organic-inorganic-hybrid perovskite nanocrystalline particle is located at about 405 nm.

Manufacturing Example 19

(139) The same process as that according to Manufacturing Example 1 was performed, and (C.sub.7H.sub.15NH.sub.3)PbBr.sub.4 was used as the organic-inorganic-hybrid perovskite. Here, the used (C.sub.7H.sub.15NH.sub.3)PbBr.sub.4 was prepared by mixing (C.sub.7H.sub.15NH.sub.3)Br with PbBr.sub.2 at a ratio of 2:1.

(140) Here, the light emission spectrum of the formed organic-inorganic-hybrid perovskite nanocrystalline particle is located at about 401 nm.

Manufacturing Example 20

(141) The same process as that according to Manufacturing Example 1 was performed, and (C.sub.12H.sub.25NH.sub.3)PbBr.sub.4 was used as the organic-inorganic-hybrid perovskite. Here, the used (C.sub.12H.sub.25NH.sub.3)PbBr.sub.4 was prepared by mixing (C.sub.12H.sub.23NH.sub.3)Br with PbBr.sub.2 at a ratio of 2:1.

(142) Here, the light emission spectrum of the formed organic-inorganic-hybrid perovskite nanocrystalline particle is located at about 388 nm.

Manufacturing Example 21

(143) The inorganic metal halide perovskite nanocrystal particle light-emitter according to an embodiment of the present invention was formed. The inorganic metal halide perovskite nanocrystal particle light-emitter was formed through an inverse nano-emulsion method, or reprecipitation method, or hot injection method.

(144) Particularly, Cs.sub.2CO.sub.3 and an oleic acid were added to octadecene (ODE) that is a non-polar solvent to react at a high temperature, thereby preparing a third solution. PbBr.sub.2, the oleic acid, and oleylamine were added to the non-polar solvent to react for one hour at a high temperature (120° C.), thereby preparing a fourth solution.

(145) Then, the third solution slowly dropped drop wise into the fourth solution that is being strongly stirred to form the inorganic metal halide perovskite (CsPbBr.sub.3) nanocrystal particle light-emitter having the 3D structure.

(146) Then, the inorganic metal halide perovskite nanocrystal particle that is dispersed in the solution was spin-coated on a glass substrate to form an inorganic halide perovskite nanocrystal particle thin film (OIP-NP film).

(147) Here, the formed inorganic metal halide perovskite nanocrystal particle has a size of about 20 nm.

Manufacturing Example 22

(148) The organic ligand of the inorganic metal halide perovskite nanocrystal particle according to Manufacturing Example 21 was substituted.

(149) First, the fourth solution in which the inorganic metal halide perovskite nanocrystal particle according to Manufacturing Example 21 is dispersed was prepared.

(150) Then, CH.sub.3(CH.sub.2).sub.8NH.sub.3I as an alkyl halide surfactant may be added to the fourth solution and heated to perform the organic ligand substitution. Thus, CH.sub.3(CH.sub.2).sub.8NH.sub.3I may become the second organic ligand surrounding the nanocrystal structure. Thus, the inorganic metal halide perovskite nanocrystal particle light-emitter, in which the organic ligand is substituted, including the inorganic metal halide perovskite nanocrystal structure having a size of about 20 nm and the CH.sub.3(CH.sub.2).sub.8NH.sub.3I organic ligand surrounding the nanocrystal structure was manufactured.

Manufacturing Example 23

(151) A light emitting device according to an embodiment of the present invention was manufactured.

(152) First, after an ITO substrate (a glass substrate coated with an ITO anode) is performed, PEDOT: PSS (AI4083 from Heraeus company) that is a conductive material was spin-coated on the ITO anode and then thermally treated for 30 minutes at a temperature of 150° C. to form a hole injection layer having a thickness of 40 nm.

(153) The solution in which the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter, in which the organic ligand is substituted, according to Manufacturing Example 8 is dispersed was spin-coated on the hole injection layer and then thermally treated for 20 minutes at a temperature of 80° C. to form an organic-inorganic-hybrid perovskite nanocrystal particle light emitting layer.

(154) Thereafter, 1,3,5-Tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBI) having a thickness of 50 nm was deposited on the organic-inorganic-hybrid perovskite nanocrystal particle light emitting layer under a high vacuum state of 1×10.sup.−7 Torr or more to form an electron transport layer, and then, LiF having a thickness of 1 nm was deposited on the electron transport layer to form an electron injection layer. Then, aluminum having a thickness of 100 nm was deposited on the electron injection layer to form a cathode, thereby manufacturing an organic-inorganic-hybrid perovskite nanocrystal particle light emitting device.

Manufacturing Example 24

(155) A solar cell according to an embodiment of the present invention was manufactured.

(156) First, after an ITO substrate (a glass substrate coated with an ITO anode) is performed, PEDOT: PSS (AI4083 from CLEVIOS PH company) that is a conductive material was spin-coated on the ITO anode and then thermally treated for 30 minutes at a temperature of 150° C. to form a hole extraction layer having a thickness of 40 nm.

(157) The organic-inorganic-hybrid perovskite nanocrystal particle, in which the organic ligand is substituted, according to Manufacturing Example 1 was mixed with Phenyl-C61-butyric acid methyl ester (PCBM) and then applied to the hole extraction layer to form a photoactive layer, and Al having a thickness of 100 nm was deposited on the photoactive layer to manufacture a perovskite nanocrystal particle solar cell.

Comparative Example 1

(158) CH.sub.3NH.sub.3PbBr.sub.3 was dissolved in dimethylformamide that is a polar solvent to manufacture a first solution.

(159) Then, the first solution was spin-coated on a glass substrate to manufacture a CH.sub.3NH.sub.3PbBr.sub.3 thin film (OIP film).

Comparative Example 2

(160) CH.sub.3NH.sub.3PbCl.sub.3 was dissolved in dimethylformamide that is a polar solvent to manufacture a first solution.

(161) Then, the first solution was spin-coated on a glass substrate to manufacture a CH.sub.3NH.sub.3PbCl.sub.3 thin film (OIP film).

Experimental Example

(162) FIG. 7 is a fluorescent image obtained by photographing emission light by irradiating ultraviolet rays onto a light-emitter according to Manufacturing Example 1, Comparative Example 1, and Comparative Example 2.

(163) Referring to FIG. 7, it is seen that an organic-inorganic-hybrid perovskite solution, which is not in the form of a nanocrystal, but in the form of a bulk, according to Comparative Example 1 and Comparative Example 2 emits dark light, but the luminescent material having the nanocrystal according to Manufacturing Example 1 emits very bright green light.

(164) Also, as a result of measuring the photoluminescence quantum yield (PLQY), it is seen that the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter according to Manufacturing Example 1 has a very high value of 52%.

(165) On the other hand, in Comparative Example 1 and Comparative Example 2, the organic-inorganic-hybrid perovskite having the form of the thin film, which is manufactured by spin-coating on the glass substrate, had a PLQY value of about 1%.

(166) FIG. 8 is a schematic view of a light-emitter according to Manufacturing Example 1 and Comparative Example 1.

(167) FIG. 8(a) is a schematic view of a light-emitter thin film (OIP film) according to Comparative Example 1, FIG. 8(b) is a schematic view of a light-emitter thin film (OIP-NP film) according to Manufacturing Example 1. Referring to FIG. 8(a), the nanocrystal particle according to Comparative Example 1 has the form of the thin film manufactured by spin-coating the first solution on the glass substrate. Referring to FIG. 8(b), the light-emitter according to Manufacturing Example 1 has the form of the nanocrystal structure 110.

(168) FIG. 9 is an image obtained by photographing a photoluminescence matrix of the light-emitter at room temperature and a low temperature according to Manufacturing Example 30 and Comparative Example 1.

(169) FIG. 9(a) is an image obtained by photographing a light emission matrix of the thin film-shaped organic-inorganic-hybrid perovskite (OIP film) according to Comparative Example 1 at a low temperature (70K), and FIG. 9(b) is an image obtained by photographing a light emission matrix of the thin film-shaped organic-inorganic-hybrid perovskite (OIP film) according to Comparative Example 1 at room temperature.

(170) FIG. 9(c) is an image obtained by photographing a photoluminescence matrix of the thin film (OIP-NP film) including the organic-inorganic-hybrid perovskite nanocrystal particle according to Manufacturing Example 1 at a low temperature (70K), and FIG. 9(d) is an image obtained by photographing a photoluminescence matrix of the thin film (OIP-NP film) of the organic-inorganic-hybrid perovskite nanocrystal particle according to Manufacturing Example 1 at room temperature.

(171) Referring to FIGS. 9(a) and 9(d), in case of the OIP-NP film (OIP-NP film) according to Manufacturing Example 1, it is seen that photoluminescence occurs at the same position as that of the OIP film according to Comparative Example 1, and color purity is more improved. Also, in case of the OIP-NP film according to Manufacturing Example 1, it is seen that photoluminescence having high color purity occurs at room temperature at the same position as that at the low temperature, and intensity of the light emission is not reduced. On the other hand, the organic-inorganic-hybrid perovskite according to Comparative Example 1 has different color purity and light emission position at room temperature and low temperature, and exciton does not emit light due to thermal ionization and delocalization of charge carriers at room temperature and thus is separated as free charge carriers and annihilated to cause low light emission intensity.

(172) FIG. 10 is a graph obtained by photographing photoluminescence of the light-emitter according to Manufacturing Example 1 and Comparative Example 1.

(173) Referring to FIG. 10, in all cases of the liquid state in which the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter is contained in the solution and the thin film state in which the thin film layer is formed by using the nanocrystal particle light-emitter according to Manufacturing Example 1, it is seen that the photoluminescence occurs at the same position as the organic-inorganic-hybrid perovskite according to Manufacturing Example 1.

(174) FIG. 11 is a schematic view of the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter, in which the organic ligand is substituted, according to an embodiment of the present invention.

(175) Referring to FIG. 11, the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter 100 manufactured through the manufacturing methods of the present invention may be substituted with the organic ligand containing a hydrophobic a phenyl group or fluorine group, for example, fluorine ammonium. Thus, since the organic-inorganic-hybrid perovskite nanocrystal particle light-emitter is substituted with this kind of ligand, it is seen that the manufactured organic-inorganic-hybrid perovskite nanocrystal particle light-emitter 100′ is more improved in durability (or stability).

(176) In the nanocrystal particle light-emitter including the organic-inorganic-hybrid perovskite nanocrystal structure, the organic-inorganic-hybrid perovskite having the crystal structure, in which the FCC and the BCC are combined with each other, may be formed in the nanocrystal particle light-emitter to form a lamellar structure in which the organic plane and the inorganic plane are alternately stacked, and also, the excitons may be confined in the inorganic plane to implement the high color purity.

(177) Also, the exciton diffusion length may be reduced, and the exciton binding energy may increase in the nanocrystal having a size of 900 nm or less to prevent the excitons from being annihilated by thermal ionization and the delocalization of the charge carriers, thereby improving the luminescent efficiency at room temperature.

(178) Also, the bandgap energy of the organic-inorganic-hybrid perovskite nanocrystal particle may be determined by the crystal structure without depending on the particle size.

(179) Furthermore, since the 2D organic-inorganic-hybrid perovskite is synthesized into the nanocrystal when compared to the 3D organic-inorganic-hybrid perovskite, the exciton binding energy may be improved to more improve the luminescent efficiency and the durability (or stability).

(180) Also, the organic ligand surrounding the organic-inorganic-hybrid perovskite or inorganic metal halide perovskite nanocrystal may be substituted with the ligand having the short length or the ligand including the phenyl group or the fluorine group to more increase the energy transfer or the charge injection in the nanocrystal structure, thereby improving the luminescent efficiency and the durability (or stability) by the hydrophobic ligands.

(181) It should be noted that the embodiments of the present invention disclosed in the present specification and drawings are only illustrative of specific examples for the purpose of understanding and are not intended to limit the scope of the present invention. It is to be understood by those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

DESCRIPTION OF SYMBOLS

(182) 100: Organic-inorganic-hybrid perovskite nanocrystal particle light-emitter 100′: Organic-inorganic-hybrid perovskite nanocrystal particle light-emitter in which organic ligand is substituted 110: Organic-inorganic-hybrid perovskite nanocrystal structure 120: First organic ligand 130: Second organic ligand