Method of forming perovskite compound thin film and method of manufacturing solar cell using the same

Abstract

The present invention provides a method for forming a perovskite compound thin film, the method comprising: a step of depositing a perovskite compound by reacting at least one compound selected from an amine compound and an amidine compound, an organometallic compound containing a divalent cation, and at least one hydrohalide; and a step of removing impurities from the perovskite compound.

Description

Technical Field

[0001] The present invention relates to a method for forming a perovskite compound thin film and a method for manufacturing a solar cell using the same. Background Art

[0002] In the related art, the solution process is mainly used in manufacturing solar cells using perovskite compounds. The solution process is that after preparing a solution by dissolving the perovskite compound in a predetermined solvent, the solution of the perovskite compound is applied to a substrate by spin coating, spray coating or slot die.

[0003] This solution process has no problem when the solution of the perovskite compound is applied to a substrate having a flat surface, but it is difficult to form a thin film with uniform thickness when the solution of the perovskite compound is applied to a crystalline silicon substrate having a pyramid structure for forming a tandem solar cell.

[0004] To solve this problem, a method of forming a film of a perovskite compound by a deposition process has been invented. However, the film of a perovskite compound formed by the deposition process has a problem that the crystal structure is easily changed when exposed to the atmospheric environment, which reduces the efficiency of the solar cell. Summary of the invention

[0005] Technical issues

[0006] The present invention is to solve the above-mentioned problems and to provide a method of forming a perovskite compound thin film and a method of manufacturing a solar cell using the same, which are capable of preventing a crystal structure from being changed while using a deposition process.

[0007] Technical Solution

[0008] In order to achieve the above-mentioned purpose, an embodiment of the present invention provides a method for forming a perovskite compound thin film, the method comprising: a process for depositing a perovskite compound by reacting at least one compound selected from amine compounds and amidine compounds, an organic metal compound containing a divalent positive ion, and at least one hydrogen halide; and a process for removing impurities in the deposited perovskite compound.

[0009] Another embodiment of the present invention provides a method for manufacturing a solar cell, the method comprising: a process for forming a crystalline solar cell; a process for forming a buffer layer on the crystalline solar cell; a process for forming a perovskite solar cell on the buffer layer; and a process for forming a first electrode on the perovskite solar cell and a second electrode on the crystalline solar cell, wherein the process for forming the perovskite solar cell comprises a process for forming a perovskite compound thin film, and wherein the process for forming the perovskite compound thin film comprises: a process for depositing a perovskite compound by reacting at least one compound selected from an amine compound and an amidine compound, an organic metal compound containing a divalent positive ion, and at least one hydrogen halide; and a process for removing impurities in the deposited perovskite compound.

[0010] Beneficial Effects

[0011] According to the present invention, the following effects can be achieved.

[0012] According to an embodiment of the present invention, when a perovskite compound is formed by a deposition process such as CVD or ALD, impurities present in a dangling bond state in the perovskite compound are removed after or during the deposition process. Therefore, the crystal structure of the perovskite compound can be prevented from changing, thereby improving the efficiency of the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a process diagram for forming a perovskite compound thin film according to an embodiment of the present invention.

[0014] Figure 2 is a crystal structure of a perovskite compound after a deposition process according to an embodiment of the present invention.

[0015] Figure 3 is a crystal structure of a perovskite compound after a deposition process and an impurity removal process according to an embodiment of the present invention.

[0016] Figure 4 is a process diagram for forming a perovskite compound thin film according to another embodiment of the present invention.

[0017] Figure 5a is a perovskite compound thin film sample obtained immediately after a deposition process according to an embodiment of the present invention.

[0018] Figure 5b is a perovskite compound thin film sample exposed to an atmospheric environment after a deposition process according to an embodiment of the present invention.

[0019] Figure 5c is a thin film sample after adding a cleaning material to the perovskite compound thin film sample exposed to an atmospheric environment after a deposition process according to an embodiment of the present invention.

[0020] Figure 6a is an XRD analysis result of a perovskite compound thin film sample exposed to an atmospheric environment after a deposition process according to an embodiment of the present invention.

[0021] Figure 6b is an XRD analysis result of a thin film sample after adding a cleaning material to the perovskite compound thin film sample exposed to an atmospheric environment after a deposition process according to an embodiment of the present invention.

[0022] Figures 7a to 7e 1 is a process cross-sectional view showing a method of manufacturing a solar cell according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The advantages and features of the present invention and the implementation method of the present invention will be explained by the embodiments described below with reference to the accompanying drawings. However, the present invention can be embodied in different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention will be thorough and complete, and will fully convey the scope of the present invention to those of ordinary skill in the art. In addition, the present invention is limited only by the scope of the claims.

[0024] The shapes, sizes, proportions, angles and quantities disclosed in the accompanying drawings for describing the embodiments of the present invention are only examples, and therefore the present invention is not limited to the details shown. Throughout the application, similar reference numerals represent similar elements. In the following description, when it is determined that the detailed description of the relevant known technology will unnecessarily obscure the key points of the present invention, such detailed description will be omitted. When using "including", "having" and "comprising" described in this specification, unless "only" is used, another component can be added. Unless otherwise specified, terms in the singular may include plural forms.

[0025] When explaining an element, although the error range is not described in detail, the element should be understood as including the error range.

[0026] When describing a positional relationship, for example, when the positional relationship between two components is described as "on", "above", "under", and "beside", unless "immediately" or "directly" is used, one or more other components may be arranged between the two components.

[0027] When describing a time relationship, for example, when describing a time sequence with "after," "subsequently," "next," and "before," discontinuous cases may be included unless "just" or "directly" is used.

[0028] It will be understood that, although the terms "first", "second", etc. can be used to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the present invention, the first element can be named as the second element, and similarly, the second element can be named as the first element.

[0029] The term "at least one" should be understood to include any and all combinations of more than one of the related listed items. For example, "at least one of the first, second, and third items" means a combination of more than two of the first, second, and third items and all items proposed by the first, second, or third items.

[0030] The features of the various embodiments of the present invention may be combined or combined with each other in part or in whole, and may interact with each other in various ways and be technically driven in a manner that is fully understandable to those of ordinary skill in the art. The embodiments of the present invention may be implemented independently of each other, or may be implemented in a mutually dependent relationship.

[0031] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0032] Figure 1 is a process diagram for forming a perovskite compound film according to an embodiment of the present invention, Figure 2 is a crystal structure of a perovskite compound after a deposition process according to an embodiment of the present invention, and Figure 3 is a crystal structure of a perovskite compound after a deposition process and an impurity removal process according to an embodiment of the present invention.

[0033] like Figure 1 As shown, the perovskite compound thin film according to an embodiment of the present invention may be formed by a process of depositing the perovskite compound and a process of removing impurities in the deposited perovskite compound.

[0034] According to an embodiment of the present invention, the perovskite compound deposition process includes depositing ABX by reacting at least one compound selected from an amine compound and an amidine compound, an organic metal compound containing a divalent positive ion, and at least one hydrogen halide via chemical vapor deposition (CVD) or atomic layer deposition (ALD). 3 Compound.

[0035] On ABX 3In the above, A may be composed of a monovalent organic cation of an amine compound, a monovalent organic cation of an amidine compound, or a monovalent organic cation of an amine compound and a monovalent organic cation of an amidine compound. A may have a structure in which a monovalent organic cation of an amine compound is contained in an x ​​ratio and a monovalent organic cation of an amidine compound is contained in an y ratio. In this case, each of x and y is greater than 0, and x+y=1.

[0036] On ABX 3 In the above formula, B is composed of divalent positive ions of organometallic compounds.

[0037] On ABX 3 In the above formula, X is composed of one or more halogen elements.

[0038] The amine compound may be selected from the group consisting of methylamine, ethylamine and phenethylamine.

[0039] The amidine compound may consist of formamidine.

[0040] The organometallic compound including a divalent positive ion may include a metal selected from the group consisting of lead (Pb), tin (Sn), germanium (Ge), antimony (Sb), bismuth (Bi), and barium (Ba).

[0041] In detail, the organometallic compound including a divalent positive ion may include a compound represented by the following Chemical Formula 1:

[0042] Chemical formula 1

[0043]

[0044] (In Chemical Formula 1, R 1 To R 12 Each independently consists of hydrogen or an alkyl group, and X is selected from the group consisting of Pb, Sn, Ge, Sb, Bi and Ba)

[0045] Alternatively, the organometallic compound containing a divalent cation may be selected from the group consisting of Pb(CH 3 ) 4 、Pb(C 2 H 5 ) 4 、Pb(SCN) 2 , (C 2 H 5 ) 3 PbOCH 2 C(CH 3 ) 3 、Pb(C11 H 19 O 2 ) 2 、Pb((CH 3 ) 3 C-COCHCO-C(CH 3 ) 3 ) 2 、Pb((C 6 H 5 ) 2 PCH 2 P(C 6 H 5 ) 2 ) 2 、Pb(N(CH 3 ) 2 C(CH 3 ) 2 OH) 2 and C 12 H 28 N 2 O 2 The group composed of Pb.

[0046] The light absorption rate, optical band gap, carrier mobility and material stability of the finally obtained perovskite compound can be adjusted according to the type of the organic metal compound containing divalent positive ions.

[0047] The hydrohalide may be selected from the group consisting of HI, HBr, HF and HCl. The optical band gap of the finally obtained perovskite compound may be adjusted according to the type of the hydrohalide.

[0048] The amine compound, the amidine compound, the organometallic compound containing a divalent positive ion, and the hydrogen halide include materials that vaporize at a temperature ranging from room temperature to 200 degrees Celsius (° C.), and preferably, include materials that vaporize at a temperature ranging from 50° C. to 150° C. Therefore, in the production of ABX 3 In the process of preparing the compound, the chemical vapor deposition (CVD) process or the atomic layer deposition (ALD) process can be performed at a temperature below 200° C. (preferably, at a temperature below 150° C.), thereby preventing the final ABX 3 The organic material in the compound is decomposed during the CVD process or the ALD process. In addition, plasma may be applied during the CVD process or the ALD process.

[0049] According to another embodiment of the present invention, the perovskite compound deposition process includes depositing CABX by reacting at least one compound selected from amine compounds and amidine compounds, at least one alkali metal compound, an organic metal compound containing a divalent positive ion, and at least one hydrogen halide via chemical vapor deposition (CVD) or atomic layer deposition (ALD). 3 Compound.

[0050] At CABX 3 In the above, A may be composed of a monovalent organic cation of an amine compound, a monovalent organic cation of an amidine compound, or a monovalent organic cation of an amine compound and a monovalent organic cation of an amidine compound.

[0051] At CABX 3 In the above, C may be composed of at least one alkali metal compound.

[0052] CA may have a structure in which a monovalent organic positive ion of an amine compound is contained in an x ​​ratio, a monovalent organic positive ion of an amidine compound is contained in an y ratio, and a monovalent positive ion of an alkali metal is contained in an z ratio. In this case, each of x, y, and z is greater than 0, and x+y+z=1.

[0053] At CABX 3 In the above formula, B is composed of a divalent positive ion, and X is composed of one or more halogen elements.

[0054] The amine compound, the amidine compound, the organometallic compound containing a divalent positive ion, and the hydrogen halide are as described above, and thus repeated descriptions thereof will be omitted.

[0055] The alkali metal compound may include a compound represented by the following Chemical Formula 2:

[0056] Chemical formula 2

[0057]

[0058] (In Chemical Formula 2, R 1 To R 6 Each independently consists of hydrogen or an alkyl group, and Y is an alkali metal)

[0059] As described above, according to another embodiment of the present invention, at least one alkali metal compound may be added to the reactants, thereby compensating for the instability of monovalent organic positive ions that are susceptible to water, heat, and plasma.

[0060] According to one embodiment, ABX is deposited by a CVD process. 3The process of preparing the compound may include simultaneously supplying at least one compound selected from amine compounds and amidine compounds, an organic metal compound containing a divalent positive ion, and at least one hydrogen halide into a process chamber.

[0061] According to one embodiment, ABX is deposited by an ALD process. 3 The process of the compound may include a process of supplying at least one compound selected from amine compounds and amidine compounds and an organic metal compound containing a divalent positive ion as a source material into a process chamber, a process of blowing off the source material, a process of supplying at least one hydrogen halide as a reaction material into the process chamber, and a process of blowing off the reaction material. The process of supplying at least one hydrogen halide as a reaction material may be performed in a plasma state and is the same as the following embodiment.

[0062] According to another embodiment, ABX is deposited by an ALD process. 3 The process of preparing a compound may include a process of supplying at least one compound selected from amine compounds and amidine compounds as a first source material into a process chamber, a process of blowing off the first source material, a process of supplying at least one hydrogen halide as a first reaction material into the process chamber, a process of blowing off the first reaction material, a process of supplying an organic metal compound containing a divalent positive ion as a second source material into the process chamber, a process of blowing off the second source material, a process of supplying at least one hydrogen halide as a second reaction material into the process chamber, and a process of blowing off the second reaction material.

[0063] According to another embodiment, ABX is deposited by an ALD process. 3 The process of preparing a compound may include a process of supplying at least one compound selected from amine compounds and amidine compounds as a first source material into a process chamber, a process of blowing off the first source material, a process of supplying at least one hydrogen halide as a first reaction material into the process chamber, a process of blowing off the first reaction material, a process of supplying an organic metal compound containing a divalent positive ion as a second source material and at least one hydrogen halide as a second reaction material into the process chamber, and a process of blowing off the second source material and the second reaction material. In this case, the first source material and the second source material may be interchangeable.

[0064] According to another embodiment, ABX is deposited by an ALD process. 3The process of preparing the compound may include a process of supplying at least one compound selected from amine compounds and amidine compounds as a first source material into the process chamber, a process of blowing off the first source material, a process of supplying at least one hydrogen halide as a first reaction material and an organic metal compound containing a divalent positive ion as a second source material into the process chamber, and a process of blowing off the first reaction material and the second source material. In this case, the first source material and the second source material may be interchangeable.

[0065] Reference Figure 2 , perovskite compounds formed by deposition processes such as CVD or ALD may have ABX 3 The compound contains the structure of the impurities.

[0066] Including ABX 3 In the crystal structure of the perovskite compound of the compound, the A compound may be composed of a hexahedral structure, for example, a cubic structure. That is, the A compound is located at the vertices of the hexahedral structure, and the hexahedral structure is formed with an upper surface and a lower surface parallel to each other and four side surfaces in contact with each of the upper surface and the lower surface.

[0067] Including ABX 3 In the crystal structure of the perovskite compound of the compound, the X compound may have an octahedral structure, for example, a regular octahedral structure, arranged in a hexahedral structure. That is, the X compound is arranged at the vertex of the octahedral structure. At this time, the upper vertex of the octahedral structure contacts the upper surface of the hexahedral structure made of the A compound, the lower vertex of the octahedral structure contacts the lower surface of the hexahedral structure made of the A compound, and the four vertices of the central rectangular structure of the octahedral structure contact the four sides of the hexahedral structure.

[0068] Including ABX 3 In the crystal structure of the perovskite compound of the compound, the B compound is arranged at the center of the hexahedral structure or the center of the octahedral structure. Therefore, the B compound may be arranged at the center of the central rectangular structure of the octahedral structure.

[0069] Eight hexahedrons are in contact with each other at one vertex made of the A compound, two hexahedrons are in contact with each other at one vertex made of the X compound, and the B compound is arranged in one hexahedron. Therefore, ABX 3 The compound may consist of 1 mole of compound A, 1 mole of compound B and 3 moles of compound X.

[0070] Impurities may be contained in the ABX 3 The impurities can be present in the crystal structure of the perovskite compound. 3The compound is chemically bonded, but may be included in a dangling bond state. Impurities may exist on the surface of the hexahedron or may exist inside the hexahedron.

[0071] The impurities may include an A compound such as methylamine, ethylamine, phenethylamine, or formamidine. An A compound that is not chemically bonded to the X compound and the B compound may be included in the ABX-containing mixture in a dangling bond state. 3 The crystal structure of the perovskite compound.

[0072] In addition, the impurity may be made of a hydrohalide (HX) such as HI, HBr, HF, or HCl. The hydrohalide (HX) that is not chemically bonded to the A compound and the B compound may be contained in the ABX containing compound in a dangling bond state. 3 The crystal structure of the perovskite compound.

[0073] When a perovskite compound is formed by a deposition process such as CVD or ALD, impurities in a dangling bond state may exist in the perovskite compound, and such impurities may easily change the crystal structure of the perovskite compound. Therefore, the present invention prevents changes in the crystal structure of the perovskite compound by removing impurities present in the perovskite compound, thereby improving the efficiency of the solar cell. The process of removing impurities will be described below.

[0074] Return to reference Figure 1 The process of removing impurities from the deposited perovskite compound includes adding a cleaning material to the deposited perovskite compound to chemically bond the impurities to the cleaning material.

[0075] In the process of adding the cleaning material, the cleaning material may be supplied in a liquid state or in a gaseous state.

[0076] The process of supplying the cleaning material in a liquid state may be performed by using a solution device such as spin coating, spray coating, slot coating, nozzle printing, or ink jetting.

[0077] The process of supplying the cleaning material in a gaseous state may be performed using a CVD or ALD chamber, wherein an evaporator or bubbler system for vaporizing the cleaning material may be connected to the CVD or ALD chamber.

[0078] The cleaning material comprises an organic material capable of reacting with at least one of an amine compound, an amidine compound, and a hydrogen halide. In particular, the cleaning material may be an organic material (e.g., C 3 H 8 O) is made.

[0079] As shown in the following reaction formula 1, in the case where the impurity is formed by, for example, methylamine, when C is supplied as a cleaning material 3 H 8 O, methylamine and C 3 H 8 O combines to form CH 3 NHOH (methylhydroxylamine) and C 3 H 8 (propane).

[0080] Reaction 1

[0081] CH 3 NH 2 (Methylamine)+C 3 H 8 O→CH 3 NHOH(Methylhydroxylamine)+C 3 H 8 (Propane)

[0082] The CH generated in reaction 1 3 NHOH (methylhydroxylamine) can be vaporized and removed by a subsequent heat treatment process. Therefore, impurities consisting of methylamine can be removed by contacting the C 3 H 8 O reacts to form CH 3 The NHOH (methylhydroxylamine) form is removed.

[0083] As shown in the following reaction formula 2, in the case where the impurity is formed of, for example, hydrogen iodide (HI), when C as a cleaning material is supplied 3 H 8 O, hydrogen iodide (HI) and C 3 H 8 O combines to form C 2 H 5 I(ethyl iodide) and CH 3 OH (methanol).

[0084] Reaction 2

[0085] HI+C 3 H 8 O→C 2 H 5 I(Ethyl Iodide)+CH 3 OH(Methanol)

[0086] The C generated in reaction 2 2 H 5 I (ethyl iodide) can be vaporized and removed by a subsequent heat treatment process. Therefore, impurities consisting of hydrogen iodide (HI) can be removed by contacting the C 3 H 8 O reacts with C2 H 5 The I (ethyl iodide) form is removed.

[0087] Reference Figure 3 , when impurities are removed by adding a cleaning material to the perovskite compound formed by the deposition process, ABX 3 Crystal structure of the compound.

[0088] In addition to impurities from Figure 2 In addition to removing the crystal structure, Figure 3 The crystal structure and Figure 2 The crystal structure of ABX 3 The repeated description of the crystal structure of the compound will be omitted.

[0089] Figure 4 is a process diagram for forming a perovskite compound thin film according to another embodiment of the present invention.

[0090] like Figure 4 As shown, a perovskite compound thin film according to another embodiment of the present invention may be formed by simultaneously performing a process of depositing a perovskite compound and a process of removing impurities in the deposited perovskite compound.

[0091] According to one embodiment, ABX is deposited by a CVD process. 3 The process of removing impurities simultaneously with the compound of the present invention may include a process of simultaneously supplying at least one compound selected from amine compounds and amidine compounds, an organic metal compound containing a divalent positive ion, at least one hydrogen halide, and an organic material constituting the cleaning material into the process chamber. In this case, an evaporator or bubbler system for vaporizing the cleaning material may be connected to the CVD chamber. In the case of the ALD process described below, an evaporator or bubbler system for vaporizing the cleaning material may be connected to the ALD chamber.

[0092] According to another embodiment, ABX is deposited by an ALD process. 3 The process for removing impurities from the cleaning material while removing impurities from the cleaning material may include a process of supplying at least one compound selected from amine compounds and amidine compounds and an organic metal compound containing divalent positive ions as source materials into the process chamber, a process of blowing away the source materials, a process of supplying at least one hydrogen halide as a reaction material and an organic material constituting a cleaning material into the process chamber, and a process of blowing away the reaction material.

[0093] According to another embodiment, ABX is deposited by an ALD process. 3The process of removing impurities from the compound simultaneously may include a process of supplying at least one compound selected from amine compounds and amidine compounds and an organic metal compound containing divalent positive ions as source materials into the process chamber, a process of blowing off the source material, a process of supplying at least one hydrogen halide as a first reaction material into the process chamber, a process of blowing off the first reaction material, a process of supplying an organic material constituting a cleaning material as a second reaction material into the process chamber, and a process of blowing off the second reaction material. In this case, the first reaction material and the second reaction material may be interchangeable.

[0094] According to another embodiment, ABX is deposited by an ALD process. 3 The process of removing impurities from the compound while removing impurities may include a process of supplying at least one compound selected from amine compounds and amidine compounds as a first source material into the process chamber, a process of blowing off the first source material, a process of supplying at least one hydrogen halide as a first reaction material into the process chamber, a process of blowing off the first reaction material, a process of supplying an organic metal compound containing divalent positive ions as a second source material into the process chamber, a process of blowing off the second source material, a process of supplying at least one hydrogen halide as the second reaction material into the process chamber, a process of blowing off the second reaction material, a process of supplying an organic material constituting a cleaning material as a third reaction material into the process chamber, and a process of blowing off the third reaction material. In this case, the first source material and the second source material may be interchanged with each other, and the first reaction material to the third reaction material may be interchanged with each other, and these principles are the same as those in the following embodiments.

[0095] According to another embodiment, ABX is deposited by an ALD process. 3 The process for removing impurities from a compound while removing impurities from the compound may include a process of supplying at least one compound selected from amine compounds and amidine compounds as a first source material into a process chamber, a process of blowing off the first source material, a process of supplying at least one hydrogen halide as a first reaction material into the process chamber, a process of blowing off the first reaction material, a process of supplying an organic metal compound containing divalent positive ions as a second source material into the process chamber, a process of blowing off the second source material, a process of supplying at least one hydrogen halide of the second reaction material and an organic material constituting a cleaning material into the process chamber, and a process of blowing off the second reaction material.

[0096] According to another embodiment, ABX is deposited using an ALD process. 3The process for simultaneously removing impurities from a compound containing divalent positive ions may include a process of supplying at least one compound selected from amine compounds and amidine compounds as a first source material into a process chamber, a process of blowing off the first source material, a process of supplying at least one hydrogen halide as a first reaction material into the process chamber, a process of blowing off the first reaction material, a process of supplying an organic metal compound containing divalent positive ions as a second source material and at least one hydrogen halide as a second reaction material into the process chamber, a process of blowing off the second source material and the second reaction material, a process of supplying an organic material constituting a cleaning material as a third reaction material into the process chamber, and a process of blowing off the third reaction material.

[0097] The process of supplying an organic material constituting the cleaning material may be performed after the process of supplying at least one compound selected from amine compounds and amidine compounds, the process of supplying an organic metal compound containing a divalent positive ion, and the process of supplying at least one hydrogen halide.

[0098] Alternatively, a process of supplying an organic material constituting a cleaning material may be performed before at least one of a process of supplying at least one compound selected from amine compounds and amidine compounds, a process of supplying an organic metal compound containing a divalent positive ion, and a process of supplying at least one hydrogen halide.

[0099] Alternatively, a process of supplying an organic material constituting a cleaning material and at least one process of supplying at least one compound selected from amine compounds and amidine compounds, a process of supplying an organic metal compound containing a divalent positive ion, and a process of supplying at least one hydrogen halide may be performed simultaneously.

[0100] Figure 5a is a perovskite compound thin film sample obtained immediately after the deposition process according to an embodiment of the present invention, Figure 5b is a perovskite compound thin film sample exposed to an atmospheric environment after a deposition process according to an embodiment of the present invention, and Figure 5c is a thin film sample after adding a cleaning material to the perovskite compound thin film sample exposed to an atmospheric environment after a deposition process according to an embodiment of the present invention.

[0101] like Figure 5a As shown, the perovskite compound thin film sample immediately after the deposition process has a normal brown color, but as Figure 5b As shown, when the perovskite compound thin film sample is exposed to the atmospheric environment, it can be seen that the color changes from the normal color of brown to the abnormal color of white due to the phase transition in the crystal structure.

[0102] In addition, if Figure 5c As shown, when cleaning the material C 3H 8 When O is added to a perovskite compound thin film sample that has changed to an abnormal white color due to exposure to an atmospheric environment using a solution process, the abnormal white color changes to a normal brown color due to a phase transition in the crystal structure.

[0103] Figure 6a is an XRD analysis result of a perovskite compound thin film sample exposed to an atmospheric environment after a deposition process according to an embodiment of the present invention, and Figure 6b is an XRD analysis result of a thin film sample after adding a cleaning material to the perovskite compound thin film sample exposed to an atmospheric environment after a deposition process according to an embodiment of the present invention. Figure 6a yes Figure 5b XRD analysis results of thin film samples, and Figure 6b yes Figure 5c XRD analysis results of thin film samples.

[0104] like Figure 6a As shown in Figure 2, when the perovskite compound film sample is exposed to the atmosphere, the crystal structure is determined to be a non-stoichiometric structure, but as Figure 6b As shown, when cleaning the material C 3 H 8 When O was added to a perovskite compound thin film sample exposed to the atmosphere using a solution process, the crystal structure was reconfirmed to be a stoichiometric structure.

[0105] Figures 7a to 7e 1 is a process cross-sectional view showing a method of manufacturing a solar cell according to an embodiment of the present invention.

[0106] First, if Figure 7a As shown, a crystalline solar cell 100 is manufactured.

[0107] The crystalline solar cell 100 is manufactured by a process of etching one surface and the other surface of a semiconductor substrate 110, such as a wafer, to form a concave-convex structure, doping a specific dopant on the one surface of the semiconductor substrate 110 to form a first semiconductor layer 120, and doping a specific dopant on the other surface of the semiconductor substrate 110 to form a second semiconductor layer 130.

[0108] Since the one surface and the other surface of the semiconductor substrate 110 are formed in the concavo-convex structure, the first semiconductor layer 120 and the second semiconductor layer 130 are formed in shapes corresponding to the concavo-convex structure.

[0109] On the other hand, the drawings show that the one surface and the other surface of the semiconductor substrate 110 are formed as a concavo-convex structure, but it is not necessarily limited thereto. The one surface of the semiconductor substrate 110 may be formed as a concavo-convex structure, and the other surface may be formed as a flat structure. Alternatively, the other surface of the semiconductor substrate 110 may be formed as a concavo-convex structure, and the one surface may be formed as a flat structure. In some cases, the one surface and the other surface of the semiconductor substrate 110 may be formed as a flat structure.

[0110] The semiconductor substrate 110 may be formed of a P-type or N-type wafer, the first semiconductor layer 120 may be doped with a dopant having a different polarity from that of the semiconductor substrate 110, and the second semiconductor layer 130 may be doped with a dopant having the same polarity as that of the semiconductor substrate 110. For example, the semiconductor substrate 110 may be made of a P-type wafer, the first semiconductor layer 120 may be doped with an N-type dopant, and the second semiconductor layer 130 may be doped with a P-type dopant to form a P+ layer.

[0111] Then, if Figure 7b As shown, a buffer layer 200 is formed on the crystalline solar cell 100 .

[0112] The buffer layer 200 is formed on the first semiconductor layer 120. Since the first semiconductor layer 120 is formed in a concavo-convex structure, the buffer layer 200 is formed in a shape corresponding to the concavo-convex structure.

[0113] The buffer layer 200 is disposed between the crystalline solar cell 100 and a perovskite solar cell 300 described below, and thus the solar cell according to the embodiment of the present invention has a structure of a tandem solar cell based on a tunnel junction.

[0114] It is preferable that the buffer layer 200 contains a material for enabling light having a long wavelength to pass through the perovskite solar cell 300 without loss to be incident on the crystalline solar cell 100. For example, the buffer layer 200 may be formed of a transparent conductive oxide, a carbonaceous conductive material, a metallic material, or a conductive polymer, and in some cases, may be doped with an n-type or p-type dopant with the material.

[0115] Then, if Figure 7c As shown, a perovskite solar cell 300 is formed on the buffer layer 200 .

[0116] Since the buffer layer 200 is formed in a concavo-convex structure, the perovskite solar cell 300 may also be formed in a concavo-convex structure.

[0117] The perovskite solar cell 300 may include a first conductive charge transfer layer disposed on the buffer layer 200 , a light absorbing layer disposed on the first conductive charge transfer layer, and a second conductive charge transfer layer disposed on the light absorbing layer.

[0118] The first conductive charge transfer layer may be formed of an electron transfer layer, and the second conductive charge transfer layer may be formed of a hole transfer layer. Alternatively, the first conductive charge transfer layer may be formed of a hole transfer layer, and the second conductive charge transfer layer may be formed of an electron transfer layer.

[0119] The electron transfer layer may include a compound including an N-type organic material such as bathocuproine (BCP), C60 or phenyl-C61-butyric acid methyl ester (PCBM), or an organic material such as ZnO, c-TiO 2 / mp-TiO 2 SnO 2 Or various N-type metal oxides such as indium zinc oxide (IZO), or N-type compounds including various organic or inorganic materials known to those skilled in the art.

[0120] The hole transfer layer may include 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-MeO-TAD), 2,2',7,7'-tetrakis(N,N-di-p-tolyl)amino-9,9-spirobifluorene (Spiro-TTB), polyaniline, polyphenol, poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) known to those skilled in the art. sulfonate, PEDOT-PSS), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], PTAA, and poly(3-hexylthiophene-2,5-diyl), P3HT), or may include various P-type metal oxides such as Ni oxide, Mo oxide, V oxide, W oxide or Cu oxide known to those of ordinary skill in the art, or may include P-type compounds containing various organic or inorganic materials known to those of ordinary skill in the art.

[0121] The light absorbing layer is made of the aforementioned perovskite compound thin film, and thus a repeated description of the light absorbing layer will be omitted.

[0122] Then, if Figure 7d As shown, a first electrode 400 is formed on the top surface of the perovskite solar cell 300 , and a second electrode 500 is formed on the bottom surface of the crystalline solar cell 100 .

[0123] Since the first electrode 400 is formed on the incident surface for incident sunlight, the first electrode 400 is patterned into a predetermined shape. The second electrode 500 may also be configured to allow reflected light of sunlight to enter the solar cell by forming a pattern of a predetermined shape, but is not limited thereto.

[0124] Then, if Figure 7e As shown, a passivation layer 600 is formed on the first electrode 400. At this time, the first electrode 400 may be exposed by etching a portion of the passivation layer 600.

[0125] Since the perovskite solar cell 300 is formed in a concavo-convex structure, the passivation layer 600 may be formed in a concavo-convex structure. The passivation layer 600 may be made of a material such as SiO, SiON, SiN, Al 2 O 3 Or various materials of MgF are formed.

[0126] In particular, the passivation layer 600 may be made of polydimethylsiloxane, and when the polydimethylsiloxane is formed on the perovskite solar cell 300 , a concavo-convex structure of micro-pyramids may be obtained.

[0127] Above, the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, but the present invention is not limited to these embodiments and can be modified in various ways without departing from the technical spirit of the present invention. Therefore, it should be understood that the above embodiments are only exemplary and non-restrictive in all aspects. It should be explained that the scope of the present invention is defined by the following claims rather than by the embodiments, and the scope and meaning of the claims and all changes and modifications derived from the concepts equivalent to the claims are included in the scope of the present invention.

Claims

1. A method for forming a perovskite compound film, comprising: A process for depositing a perovskite compound by reacting at least one compound selected from an amine compound and an amidine compound, an organometallic compound containing a divalent positive ion, and at least one hydrohalide; as well as A process for removing impurities from the deposited perovskite compound.

2. The method for forming a perovskite compound thin film according to claim 1, wherein: The impurities are contained in a crystal structure of the perovskite compound in a dangling bond state.

3. The method for forming a perovskite compound thin film according to claim 2, wherein: The impurity includes at least one compound selected from the amine compound and the amidine compound that has not reacted with the organic metal compound including a divalent positive ion and the at least one hydrogen halide, and exists in a dangling bond state.

4. The method for forming a perovskite compound thin film according to claim 2, wherein: The impurities include at least one hydrogen halide that has not reacted with the at least one compound selected from the amine compounds and the amidine compounds and the organic metal compound including a divalent positive ion, and exist in a dangling bond state.

5. The method for forming a perovskite compound thin film according to claim 1, wherein: The process of removing the impurities includes a process of reacting the impurities with the organic material by supplying an organic material to the perovskite compound.

6. The method for forming a perovskite compound thin film according to claim 5, wherein: The organic material is formed of a material capable of reacting with at least one of an amine compound, an amidine compound, and a hydrogen halide.

7. The method for forming a perovskite compound thin film according to claim 6, wherein: The organic material includes carbon (C), hydrogen (H), and oxygen (O).

8. The method for forming a perovskite compound thin film according to claim 7, wherein: The organic material includes C3H8O.

9. The method for forming a perovskite compound thin film according to claim 1, wherein: The impurities include methylamine in a dangling bond state, and the process of removing the impurities includes adding C3H8O to the perovskite compound to react the methylamine in a dangling bond state with the C3H8O and generate CH3NHOH and C3H8.

10. The method for forming a perovskite compound thin film according to claim 1, wherein: The impurities include hydrogen iodide in a dangling bond state, and the process of removing the impurities includes adding C3H8O to the perovskite compound so that the hydrogen iodide in a dangling bond state reacts with the C3H8O and generates C2H5I and CH3OH.

11. The method for forming a perovskite compound thin film according to claim 1, wherein: The process of removing the impurities includes: after the process of depositing the perovskite compound, a process of reacting an organic material with the impurities, and The process of reacting the organic material with the impurities includes adding the organic material in a solution state to the perovskite compound.

12. The method for forming a perovskite compound thin film according to claim 1, wherein: The process of removing the impurities includes: after the process of depositing the perovskite compound, a process of reacting an organic material with the impurities, and The process of reacting the organic material with the impurities includes supplying the organic material into a chamber through an evaporator or a bubbler.

13. The method for forming a perovskite compound thin film according to claim 1, wherein: The process of depositing the perovskite compound and the process of removing the impurities are simultaneously performed in a chamber.

14. The method for forming a perovskite compound thin film according to claim 13, wherein: The process of depositing the perovskite compound and the process of removing the impurities include: A process of supplying a first source material comprising the at least one compound selected from the amine compound and the amidine compound; a process of supplying a second source material comprising the organometallic compound having a divalent positive ion; a process for supplying a first reactive material comprising the at least one hydrohalide; and A process of supplying a second reaction material including the organic material that reacts with the impurity.

15. The method for forming a perovskite compound thin film according to claim 14, wherein: The process of supplying the second reactive material is performed after the process of supplying the first source material, the process of supplying the second source material, and the process of supplying the first reactive material.

16. The method for forming a perovskite compound thin film according to claim 14, wherein: The process of supplying the second reactive material is performed before at least one of the process of supplying the first source material, the process of supplying the second source material, and the process of supplying the first reactive material.

17. The method for forming a perovskite compound thin film according to claim 14, wherein: The process of supplying the second reaction material and at least one of the process of supplying the first source material, the process of supplying the second source material, and the process of supplying the first reaction material are performed simultaneously.

18. A method for manufacturing a solar cell, comprising: A process for forming a crystalline solar cell; A process for forming a buffer layer on the crystalline solar cell; A process for forming a perovskite solar cell on the buffer layer; as well as a process of forming a first electrode on the perovskite solar cell and a second electrode on the crystalline solar cell, Wherein, the process of forming the perovskite solar cell includes a process of forming a perovskite compound film, and Wherein, the process of forming the thin film of the perovskite compound includes: A process for depositing a perovskite compound by reacting at least one compound selected from an amine compound and an amidine compound, an organometallic compound containing a divalent positive ion, and at least one hydrogen halide; and A process for removing impurities from the deposited perovskite compound.

Images