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

Abstract

The present invention provides a method for forming a thin film of a perovskite compound, comprising a process of supplying a B precursor to a cavity; a process of first supplying an X precursor to the cavity; and a process of supplying an A precursor to the cavity, wherein the B precursor comprises an organometallic compound comprising a divalent positive ion, the X precursor comprises hydrogen halide, and the A precursor comprises at least one compound selected from the group consisting of amino compounds and amidine compounds, wherein the process of supplying the A precursor is performed after the process of supplying the B precursor and the process of first supplying the X precursor, and a method for manufacturing a solar cell using the present invention.

Description

Method for forming thin film of perovskite compound and method for manufacturing solar cell using the same The present invention relates to a method for forming a thin film of a perovskite compound and a method for manufacturing a solar cell using the same. Traditionally, solution-based processes have been used to manufacture solar cells using perovskite compounds. These processes involve applying a liquid perovskite compound to a substrate by dissolving it in a pre-determined solvent via spin coating, spray coating, or slot die deposition. This solution process presents no problem when the perovskite compound is applied to a substrate with a flat surface, but it is difficult to form a thin film with uniform thickness when the perovskite compound is applied to a crystalline silicon substrate having a pyramid structure used to form tandem solar cells. [Technical Issues] The present invention aims to solve the above-mentioned problems and to provide a method for forming a thin film of a perovskite compound using a deposition process (particularly atomic layer deposition), and a method for manufacturing a solar cell using the same. [Technical means] To achieve the above objectives, one embodiment of the present invention provides a method for forming a thin film of a perovskite compound, comprising a process of supplying a B precursor into a chamber; a process of supplying an X precursor into the chamber for a first time; and a process of supplying an A precursor into the chamber, wherein the B precursor comprises an organometallic compound containing a divalent positive ion, the X precursor comprises a hydrogen halide, and the A precursor comprises at least one compound selected from the group consisting of an amino compound and an amidine compound, and wherein the process of supplying the A precursor is performed after the process of supplying the B precursor and the process of supplying the X precursor for the first time. The process of supplying the B precursor may include a process of allowing the B precursor to adsorb onto a substrate. The process of supplying the X precursor for the first time may include forming an intermediate material made of a BXn (n<3) compound on the substrate by reacting the B precursor with the X precursor. The process of supplying the A precursor may include forming an ABXn (n<3) compound on the substrate by reacting the intermediate material made of the BXn (n<3) compound with the A precursor. A may include at least one monovalent organic cation selected from the group consisting of monovalent organic cations of amino compounds and monovalent organic cations of amidine compounds. B may include a divalent cation. And X may include a halogen compound. The method for forming a thin film of a perovskite compound may further include a purge process performed during at least one of a period between a process of supplying the B precursor and a first process of supplying the X precursor, a period between a first process of supplying the X precursor and a process of supplying the A precursor, and a period after the process of supplying the A precursor. The method for forming a thin film of a perovskite compound may further include a process of supplying an X precursor into the chamber for a second time after the process of supplying an A precursor. The process of supplying the X precursor into the chamber for the second time may include a process of applying power for plasma formation. The method for forming a thin film of a perovskite compound may further include performing a purge process during at least one of a period between a process of supplying the B precursor and a process of supplying the X precursor for the first time, a period between a process of supplying the X precursor for the first time and a process of supplying the A precursor, a period between a process of supplying the A precursor and a process of supplying the X precursor for the second time, and a period after the second supply of the X precursor. The process of supplying the B precursor may include a process of allowing the B precursor to be adsorbed onto the substrate, and the process of supplying the X precursor for the first time may include forming a main intermediate material made of a BXn (n<3) compound on the substrate by reacting the B precursor with the X precursor, wherein the process of supplying the A precursor may include a process of forming a secondary intermediate material made of an ABXn (n<3) compound on the substrate by reacting the main intermediate material made of the BXn (n<3) compound with the A precursor, wherein the process of supplying the X precursor for the second time may include forming a secondary intermediate material made of an ABXn (n<3) compound on the substrate by reacting the secondary intermediate material made of the ABXn (n<3) compound with the X precursor. 3 compound is formed on a substrate, wherein A may include at least one monovalent organic cation selected from the group consisting of monovalent organic cations of amino compounds and monovalent organic cations of amidine compounds, B may include a divalent cation, and X may include a halogen compound. The method for forming a thin film of a perovskite compound may further include supplying a C precursor into the chamber during the process of supplying the B precursor, wherein the C precursor may include at least one alkali metal-based compound. The process of supplying the B precursor and the C precursor may include a process of allowing the B precursor and the C precursor to be adsorbed onto a substrate, and the process of supplying the X precursor for the first time may include forming an intermediate material made of a CBXn (n<3) compound on the substrate by reacting the B precursor and the C precursor with the X precursor. The process of supplying the A precursor may include a process of forming a CABXn (n<3) compound on the substrate by reacting the intermediate material made of the CBXn (n<3) compound with the A precursor, and A may include at least one monovalent organic cation selected from the group consisting of monovalent organic cations of amino compounds and monovalent organic cations of amidine compounds, B may include a divalent cation, C may include an alkali metal, and X may include a halogen compound. The method for forming a thin film of a perovskite compound may further include a process of supplying a crystal control material into the chamber between the process of supplying the X precursor for the first time and the process of supplying the A precursor. The crystal control material may comprise pyridine or a pyridine derivative. The process of supplying the X precursor into the chamber for the first time may include a process of applying power for plasma formation. Another embodiment of the present invention provides a method for forming a thin film of a perovskite compound, comprising a process of supplying a B precursor and a C precursor into a chamber; and a process of supplying an X precursor into the chamber for a first time, wherein the B precursor comprises an organometallic compound containing a divalent positive ion, the C precursor comprises at least one alkali metal-based compound, and the X precursor comprises hydrogen halide, and the process of supplying the X precursor for the first time is performed after the processes of supplying the B precursor and the C precursor. Another embodiment of the present invention provides a method for forming a thin film of a perovskite compound, comprising a process of supplying a C precursor into a chamber; a process of supplying a B precursor into the chamber; and a process of supplying an X precursor into the chamber for a first time, wherein the B precursor comprises an organometallic compound containing a divalent positive ion, the C precursor comprises at least one alkali metal-based compound, and the X precursor comprises hydrogen halide, wherein the process of supplying the C precursor is performed before the process of supplying the B precursor and the process of supplying the X precursor for the first time. Another embodiment of the present invention provides a method for manufacturing a solar cell, comprising forming a crystalline solar cell; forming a buffer layer on a bulk solar cell; forming a perovskite solar cell on the buffer layer; and forming a first electrode on the perovskite solar cell, and forming a second electrode on the crystalline solar cell, wherein forming the perovskite solar cell comprises the method for forming a thin film of a perovskite compound as described above. 〔Beneficial Effects〕 According to the present invention, the following effects can be achieved. According to one embodiment of the present invention, since the perovskite compound is formed by atomic layer deposition, a tandem solar cell can be easily formed by applying the perovskite compound to a crystalline silicon substrate having a concavo-convex structure. According to one embodiment of the present invention, after the B precursor supply process and the X precursor supply process, the ABX can be easily prepared by performing the A precursor supply process. 3 perovskite compounds. According to one embodiment of the present invention, because the A precursor supply process is performed after the BXn (n≤3) intermediate material is formed, the compound A of the A precursor is not exposed to the plasma, and thus the intermediate material of BXn (n≤3) can react with the A precursor without breaking the chemical bonds of the compound A of the A precursor. According to one embodiment of the present invention, the X precursor is mainly supplied to form a primary intermediate material of a BXn (n<3) compound, the A precursor is supplied to form a secondary intermediate material of an ABXn (n<3) compound, and then the X precursor is secondarily supplied to form an ABXn (n<3) compound. 3 perovskite compound thin film, thereby enabling the process conditions in the vacuum chamber to be more flexibly adjusted. According to an embodiment of the present invention, during the secondary supply process of the X precursor, when the power source for plasma formation is maintained in an off state, it is possible to prevent chemical bond breaking of compound A in the secondary intermediate material of ABXn (n<3). The advantages and features of the present invention, as well as methods of implementing the same, will be illustrated through the following embodiments described with reference to the accompanying drawings. However, the present invention may be embodied in various forms and should not be limited to the embodiments described herein. Rather, these embodiments are provided to enable a thorough and complete understanding of the present invention and to fully convey the scope of the invention to those skilled in the art. Furthermore, the present invention is defined solely by the scope of the claims. The shapes, sizes, proportions, angles, and quantities disclosed in the drawings for describing the embodiments of the present invention are exemplary only, and the present invention is not limited to the details shown. Similar reference numerals throughout the text represent similar elements. In the following description, when a detailed description of the relevant conventional technology is determined to be unnecessary to obscure the key points of the present invention, such detailed description will be omitted. When using the words "comprising," "having," and "including" described in this specification, another component may be added unless "only" is used. Unless otherwise specified, terms in the singular may include plural forms. In explaining an element, although an error is not described in detail, the element should be construed as including such an error. When describing a positional relationship, for example, when using "on", "above", "below" and "next to" to describe the positional relationship between two components, unless terms such as "directly" or "directly" are used, one or more other components may be disposed between the two components. When describing a temporal relationship, for example, when describing a time sequence using “after,” “subsequently,” “next,” and “before,” discontinuities may be included unless terms such as “immediately” or “directly” are used. It will be understood that although the terms "first," "second," etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are merely used to distinguish between elements. For example, a first element may be named a second element, and similarly, a second element may be named a first element without departing from the scope of the present invention. The term "at least one" should be understood to include any and all combinations of one or more of the listed elements. For example, "at least one of a first element, a second element, and a third element" means a combination of two or more of the first element, the second element, and the third element, as well as all elements selected from the first element, the second element, and the third element. The features of the various embodiments of the present invention may be coupled 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 understood by those skilled in the art. The embodiments of the present invention may be implemented independently of each other, or in a mutually related relationship. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the relevant drawings. FIG. 1 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to one embodiment of the present invention. As shown in FIG1 , the perovskite compound ABX according to one embodiment of the present invention The thin film of 3 can be formed by atomic layer deposition (ALD) in a vacuum chamber. Specifically, the atomic layer deposition (ALD) includes a process of supplying a B precursor S10, a first purge process S20, a process of supplying an X precursor while a power source for plasma formation is kept on S30, a second purge process S40, a process of supplying an A precursor S50, and a third purge process S60. The process S10 of supplying the B precursor includes a process of supplying the B precursor onto the substrate while the substrate is loaded into the vacuum chamber so as to adsorb the B precursor onto the substrate. The B precursor may include an organometallic compound including a divalent positive ion, and B may include a divalent positive ion. 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). In detail, the organometallic compound including a divalent positive ion may include a compound represented by the following Chemical Formula 1: Chemical formula 1 In Chemical Formula 1, R 1 to R 12 Each is independently composed of hydrogen or an alkyl group, and X is selected from the group consisting of Pb, Sn, Ge, Sb, Bi and Ba. Alternatively, the organometallic compound containing a divalent cation may be selected from the group consisting of Pb(CH 3) 4. Pb(C 2H 5) 4. Pb(SCN), (C 2H 5) 3PbOCH 2C(CH 3) 3. Pb(C 11 H 19 O 2) 2. Pb((CH 3) 3C-COCHCO-C(CH 3) 3) 2. Pb((C 6H 5) 2PCH 2P(C 6H 5) 2) 2. Pb(N(CH 3) 2C(CH 3) 2OH) 2 and C 12 H 28 N 2O A group consisting of 2Pb. The first purge process S20 may include a process of removing the residual B precursor without being adsorbed onto the substrate by supplying a first purge gas into the vacuum chamber. The process S30 of supplying the X precursor while the power source for plasma formation is kept on may include the step of supplying the X precursor into the vacuum chamber so that the B precursor adsorbed on the substrate reacts with the supplied X precursor to form BX. 3. The intermediate material of the compound is formed on the substrate. The X precursor may include a hydrogen halide, and X may include a halogen compound. The hydrogen halide may be selected from the group consisting of HI, HBr, HF, and HCl. In some cases, the X precursor may be supplied while the power source for plasma formation is maintained in an off state rather than in an on state. The power source for plasma formation may be applied only for a portion of the process period for supplying the X precursor. The secondary purge process S40 may include supplying a second purge gas into the vacuum chamber to remove the X precursor that has not reacted on the substrate and remains. The second purge gas may be the same as the first purge gas, but in some cases may be different from the first purge gas. The process of supplying the A precursor S50 may include a process of supplying the A precursor into a vacuum chamber so that the BX formed on the substrate 3 compound reacts with the A precursor to make ABX A thin film of a perovskite compound of the 3 compound is formed on a substrate. The precursor A may include at least one compound selected from the group consisting of an amino compound and an amidino compound. A may consist of a monovalent organic cation of an amino compound, a monovalent organic cation of an amidino compound, or both. A may have a structure in which the monovalent organic cation of the amino compound is contained in a ratio of x and the monovalent organic cation of the amidino compound is contained in a ratio of y. In this case, each of x and y is greater than 0, and x + y = 1. The amino compound may be selected from the group consisting of methylamine, ethylamine, and phenethylamine. The amidine compound may be composed of formamidine. The third purge process S60 may include a process of removing the precursor A that has not reacted on the substrate by supplying a third purge gas into the vacuum chamber. The third purge gas may be the same as the first purge gas or the second purge gas, but in some cases may be different from the first purge gas or the second purge gas. Precursor A, Precursor B, and Precursor X are made of materials that evaporate at a temperature in the range of room temperature to 200°C (preferably in the range of 50°C to 150°C). Therefore, ABX can be manufactured by atomic layer deposition (ALD) at a temperature below 200°C (preferably below 150°C). 3. The process of perovskite compound. Therefore, during the ALD process, the final ABX 3. Decomposition of organic matter in the compound. According to one embodiment of the present invention, the A precursor supply process S50 is performed after the B precursor supply process S10 and the X precursor supply process S30. 3 is formed on the substrate, and then the above-mentioned BX 3 compounds react with precursor A to easily prepare ABX 3 perovskite compounds. If the A precursor supply process S50 is performed before the B precursor supply process S10 so that the substrate is The intermediate material made of the compound of 3 is formed first, and then AX 3 compound reacts with B precursor, it cannot easily produce ABX 3 perovskite compounds. This is because AX The reaction between compound 3 and precursor B does not occur well. Furthermore, if the A precursor supply process S50 is performed before the B precursor supply process S10, and then the process S30 of supplying the X precursor is performed while the power source for plasma formation is kept on, the chemical bonds of the compound A in the A precursor made of an organic material are broken by the plasma, so that AX 3 Intermediate materials will not be easily obtained, and the final ABX 3 Perovskite compounds cannot be easily obtained. On the other hand, according to one embodiment of the present invention, since the A precursor supply process S50 is performed at BX 3. The intermediate material is formed after the compound A in the precursor A is not exposed to the plasma. 3. The perovskite compound reacts while the chemical bonds of the compound A in the precursor A are not broken, and the final ABX is easily obtained. 3. Perovskite compounds. FIG. 2 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. As shown in FIG2 , a perovskite compound (ABX) according to another embodiment of the present invention can be formed in a vacuum chamber by atomic layer deposition (ALD). 3), specifically, the atomic layer deposition (ALD) includes a process of supplying a B precursor S10, a first purge process S20, a process of supplying an X precursor for the first time while a power source for plasma formation is maintained in an on state S30, a second purge process S40, a process of supplying an A precursor S50, a third purge process S60, a process of supplying an X precursor for the second time while a power source for plasma formation is maintained in an on state or an off state S70, and a fourth purge process S80. Since the process of supplying the B precursor S10 and the first purge process S20 are the same as those of supplying the B precursor S10 and the first purge process S20 in FIG. 1 , repeated descriptions thereof will be omitted. The process S30 of supplying the X precursor for the first time while the power source for plasma formation is maintained in an on state may include a process of supplying the X precursor into the vacuum chamber and reacting the B precursor adsorbed on the substrate with the supplied X precursor to form a main intermediate material made of a BXn (n<3) compound on the substrate. Since the X precursor and the compound X are the same as those of FIG. 1 , repeated descriptions thereof will be omitted. Since the second purge process S40 is the same as the second purge process S40 of FIG. 1 , repeated description thereof will be omitted. The process S50 of supplying the A precursor may include supplying the A precursor into a vacuum chamber and reacting the BXn (n<3) compound formed on the substrate with the supplied A precursor to form a secondary intermediate material made of the ABXn (n<3) compound on the substrate. Since the A precursor and compound A are the same as those of the A precursor and compound A described above in FIG. 1 , repeated descriptions thereof will be omitted. The third purge process S60 may include a process of removing the precursor A that has not reacted on the substrate by supplying a third purge gas into the vacuum chamber. The third purge gas may be the same as the first purge gas or the second purge gas, but in some cases may be different from the first purge gas or the second purge gas. The process S70 of supplying the X precursor for the second time while the power source for plasma formation is maintained in the on state or the off state may include supplying the X precursor into the vacuum chamber and reacting the ABXn (n<3) compound formed on the substrate with the second supplied X precursor to form the ABXn (n<3) compound. 3. Process for forming a thin film of a perovskite compound on a substrate. The X precursor in process S70 may be the same as or different from the X precursor in process S30 . The fourth purge process S80 may include supplying a fourth purge gas into the vacuum chamber to remove any remaining X precursor that has not reacted on the substrate. The fourth purge gas may be the same as the first purge gas, the second purge gas, or the third purge gas, but in some cases may be different from the first purge gas, the second purge gas, or the third purge gas. According to another embodiment of the present invention, the X precursor is supplied first to form a primary intermediate material of a BXn (n<3) compound, the A precursor is supplied to form a secondary intermediate material of an ABXn (n<3) compound, and then the X precursor is supplied a second time to form an ABXn (n<3) compound. 3 perovskite compound thin film, thereby more flexibly controlling the process conditions in the vacuum chamber. Meanwhile, the secondary intermediate material made of an ABXn (n<3) compound is formed on the substrate through the precursor A supply process S50. Because compound A, made of an organic material, chemically bonds to compound B and compound X, the chemical bonds in compound A are not easily broken even when the power source for plasma formation is turned on during the second X precursor supply process S70. Therefore, it is possible to keep the power source for plasma formation turned on during the second X precursor supply process S70. However, during the second supply process S70 of the X precursor, in order to prevent the chemical bonds of the compound A from being broken in the second intermediate material made of the ABXn (n<3) compound, it is desirable to maintain the power supply for plasma formation in an off state during the second supply process S70 of the X precursor. FIG. 3 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. As shown in FIG3 , a perovskite compound (ABX) according to another embodiment of the present invention can be formed in a vacuum chamber by atomic layer deposition (ALD). 3), specifically, the atomic layer deposition (ALD) includes a process of supplying a B precursor and a C precursor S10, a first purge process S20, a process of supplying an X precursor for the first time while a power source for plasma formation is kept on S30, a second purge process S40, a process of supplying an A precursor S50, and a third purge process S60. The process S10 of supplying the B precursor and the C precursor includes a process of supplying the B precursor and the C precursor onto the substrate while the substrate is loaded into the vacuum chamber, so that the B precursor and the C precursor are adsorbed onto the substrate. The B precursor and the C precursor can be supplied simultaneously. Since the B precursor and compound B are the same as those of FIG. 1 , repeated descriptions thereof will be omitted. The C precursor may include at least one alkali metal-based compound. Compound C may include at least one alkali metal, such as cesium (Cs). The alkali metal-based compound may include a compound represented by the following Chemical Formula 2: Chemical formula 2 In Chemical Formula 2, R 1 to R 6 Each is independently composed of hydrogen or an alkyl group, and Y is an alkali metal. As described above, according to another embodiment of the present invention, at least one alkali metal-based compound is added to the reactants to compensate for the unstable characteristics of the monovalent organic cations that are susceptible to water, heat, and plasma. The first purge process S20 may include supplying a first purge gas into the vacuum chamber to remove the B precursor and the C precursor remaining on the substrate without being adsorbed. The process S30 of supplying the X precursor while the power source for plasma formation is kept on may include the step of supplying the X precursor into the vacuum chamber so that the B precursor and the C precursor adsorbed on the substrate react with the supplied X precursor to form CBX. 3. The intermediate material of the compound is formed on the substrate. The X precursor and compound X are the same as the X precursor and compound X in FIG. 1 . The second purge process S40 is the same as the second purge process S40 of FIG. 1 . The process of supplying the A precursor S50 may include supplying the A precursor into a vacuum chamber to form the CBX on the substrate. 3 compound reacts with A precursor to make CABX A thin film of a perovskite compound of the 3 compound is formed on a substrate. Precursor A and compound A are the same as those in FIG. 1 . CA may have a structure in which a monovalent organic positive ion of an amino compound is contained at a ratio of x, a monovalent organic positive ion of an amidine compound is contained at a ratio of y, and a monovalent positive ion of an alkali metal is contained at a ratio of z. In this case, each of x, y, and z is greater than 0, and x+y+z=1. The third purge process S60 may include a process of removing the precursor A that has not reacted on the substrate by supplying a third purge gas into the vacuum chamber. The third purge gas may be the same as the first purge gas or the second purge gas, but in some cases may be different from the first purge gas or the second purge gas. FIG. 4 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. As shown in FIG4 , a perovskite compound (ABX) according to another embodiment of the present invention can be formed in a vacuum chamber by atomic layer deposition (ALD). 3), specifically, the atomic layer deposition (ALD) includes a process S10 of supplying a B precursor and a C precursor, a first purge process S20, a process S30 of supplying an X precursor for the first time while a power source for plasma formation is maintained in an on state, a second purge process S40, a process S50 of supplying an A precursor, a third purge process S60, a process S70 of supplying an X precursor for the second time while a power source for plasma formation is maintained in an on state or an off state, and a fourth purge process S80. Since the process S10 of supplying the B precursor and the C precursor and the first purge process S20 are the same as the process S10 of supplying the B precursor and the C precursor and the first purge process S20 in FIG. 3 , repeated descriptions thereof will be omitted. The process S30 of supplying the X precursor for the first time while the power source for plasma formation is kept on may include supplying the X precursor into the vacuum chamber and reacting the B precursor and the C precursor adsorbed on the substrate with the supplied X precursor, thereby forming a main intermediate material made of a CBXn (n<3) compound on the substrate. Since the X precursor and the compound X are the same as those of FIG. 3 , repeated descriptions thereof will be omitted. Since the second purge process S40 is the same as the second purge process S40 of FIG. 3 , repeated description thereof will be omitted. The process S50 of supplying the A precursor may include supplying the A precursor into a vacuum chamber and reacting the CBXn (n<3) compound formed on the substrate with the supplied A precursor to form a secondary intermediate material made of the CABXn (n<3) compound on the substrate. Since the A precursor and compound A are the same as those of the A precursor and compound A described above in FIG. 3 , their repeated description will be omitted. The third purge process S60 may include a process of removing the precursor A that has not reacted on the substrate by supplying a third purge gas into the vacuum chamber. The third purge gas may be the same as the first purge gas or the second purge gas, but in some cases may be different from the first purge gas or the second purge gas. The process S70 of supplying the X precursor for the second time while the power source for plasma formation is maintained in the on state or the off state may include supplying the X precursor into the vacuum chamber and reacting the CABXn (n<3) compound formed on the substrate with the second supplied X precursor to form CABXn. 3. Process for forming a thin film of a perovskite compound on a substrate. The X precursor in process S70 may be the same as or different from the X precursor in process S30 . The fourth purge process S80 may include supplying a fourth purge gas into the vacuum chamber to remove any remaining X precursor that has not reacted on the substrate. The fourth purge gas may be the same as the first purge gas, the second purge gas, or the third purge gas, but in some cases may be different from the first purge gas, the second purge gas, or the third purge gas. According to another embodiment of the present invention, the X precursor is supplied first to form a primary intermediate material of a CBXn (n<3) compound, the A precursor is supplied to form a secondary intermediate material of a CABXn (n<3) compound, and then the X precursor is supplied a second time to form a thin film of the perovskite compound, thereby more flexibly controlling the process conditions in the vacuum chamber. Meanwhile, the secondary intermediate material made of a CABXn (n<3) compound is formed on the substrate through the precursor A supply process S50. Because compound A, made of an organic material, chemically bonds to compound C, compound B, and compound X, the chemical bonds in compound A are not easily broken even when the power source for plasma formation is turned on during the second X precursor supply process S70. Therefore, it is possible to keep the power source for plasma formation turned on during the second X precursor supply process S70. However, during the second supply process S70 of the X precursor, in order to prevent the chemical bonds of the compound A from being broken in the second intermediate material made of the CABXn (n<3) compound, it is desirable to maintain the power supply for plasma formation in an off state during the second supply process S70 of the X precursor. FIG. 5 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. FIG. 5 is different from FIG. 1 in that a pyridine supplying process S43 and a third purge process S46 are additionally performed between the second purge process S40 and the process S50 of supplying the A precursor. According to another embodiment of the present invention, pyridine or a pyridine derivative can be supplied to the BX 3 intermediate materials made from compounds, and then supply precursor A to improve the final ABX 3. Crystalline Properties of Compounds In the following description, pyridine or pyridine derivatives are collectively referred to as pyridine. The pyridine derivative can include, but is not limited to, 4-methylpyridine or 4-tert-butylpyridine. In addition to pyridine, ABX A crystal control material or growth control material for the perovskite compound of the 3-compound may also be provided. The crystal control material or growth control material can improve the crystal stability by removing dangling bonds in the crystal through a passivation effect. In FIG5 , the third purge process S46 may include a process for removing pyridine or a pyridine derivative remaining on the substrate by supplying a third purge gas into the vacuum chamber. Also, in FIG5 , the purge process S50 performed after the process of supplying the A precursor becomes the fourth purge process S60 due to the addition of the third purge process S46. FIG. 6 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. FIG. 6 is different from FIG. 2 in that a pyridine supplying process S43 and a third purge process S46 are additionally performed between the second purge process S40 and the process S50 of supplying the A precursor. In FIG. 6 , the third purge process S46 may include a process of removing pyridine or pyridine derivatives remaining on the substrate by supplying a third purge gas into the vacuum chamber. 6 , since the third purge process S46 is added, the purge process performed after the process S50 of supplying the A precursor becomes the fourth purge process S60, and the purge process performed after the process S70 of supplying the X precursor for the second time while the power source for plasma formation is maintained in the on state or the off state becomes the fifth purge process S80. FIG. 7 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. FIG. 7 is different from FIG. 3 in that a process of supplying pyridine S43 and a third purge process S46 are additionally performed between the second purge process S40 and the process of supplying the A precursor S50 . In FIG. 7 , the third purge process S46 may include a process of removing pyridine or pyridine derivatives remaining on the substrate by supplying a third purge gas into the vacuum chamber. Meanwhile, in FIG. 7 , since the third purge process S46 is added, the purge process performed after the process S50 of supplying the A precursor becomes the fourth purge process S60 . FIG. 8 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. FIG. 8 is different from FIG. 4 in that a process of supplying pyridine S43 and a third purge process S46 are additionally performed between the second purge process S40 and the process of supplying the A precursor S50 . In FIG. 8 , the third purge process S46 may include a process of removing pyridine or pyridine derivatives remaining on the substrate by supplying a third purge gas into the vacuum chamber. 8 , since the third purge process S46 is added, the purge process performed after the process S50 of supplying the A precursor becomes the fourth purge process S60, and the purge process performed after the process S70 of supplying the X precursor for the second time while the power source for plasma formation is maintained in the on state or the off state becomes the fifth purge process S80. FIG. 9 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. As shown in FIG9 , a perovskite compound (CBX) according to another embodiment of the present invention can be formed in a vacuum chamber by atomic layer deposition (ALD). 3), specifically, the atomic layer deposition (ALD) includes a process of supplying a B precursor and a C precursor S10, a first purge process S20, a process of supplying an X precursor for the first time while a power source for plasma formation is kept on S30, and a second purge process S40. Since each process is the same as above, repeated description will be omitted. This principle also applies to the following embodiments. FIG. 10 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to one embodiment of the present invention. As shown in FIG10 , the perovskite compound CBX according to one embodiment of the present invention can be formed in a vacuum chamber by atomic layer deposition (ALD). 3 thin film, specifically, the atomic layer deposition (ALD) includes a process of supplying a C precursor S10, a first purge process S20, a process of supplying a B precursor S30, a second purge process S40, a process of supplying an X precursor while a power source for plasma formation is maintained in an on state S50, and a third purge process S60. FIG. 11 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to an embodiment of the present invention. As shown in FIG11 , the perovskite compound CBX according to one embodiment of the present invention can be formed in a vacuum chamber by atomic layer deposition (ALD). 3 thin film, specifically, the atomic layer deposition (ALD) includes a process of supplying a B precursor and a C precursor S10, a first purge process S20, a process of supplying an X precursor while a power source for plasma formation is maintained in an on state S30, a second purge process S40, a process of supplying pyridine S50, and a third purge process S60. FIG. 12 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to an embodiment of the present invention. As shown in FIG12 , the perovskite compound CBX according to one embodiment of the present invention can be formed in a vacuum chamber by atomic layer deposition (ALD). 3 thin film, specifically, the atomic layer deposition (ALD) includes a process S10 of supplying a C precursor, a first purge process S20, a process S30 of supplying a B precursor, a second purge process S40, a process S50 of supplying an X precursor while a power source for plasma formation is maintained in an on state, a third purge process S60, a process S70 of supplying pyridine, and a fourth purge process S80. The embodiments of FIG. 9 to FIG. 12 may further include a process of supplying an X precursor while a power source for plasma formation is maintained in an on state or an off state after each purge process, and a subsequent purge process. FIG13A is a diagram illustrating the crystal properties of a thin film of a perovskite compound prepared according to one embodiment of the present invention, and FIG13B is a diagram illustrating the crystal properties of a thin film of a perovskite compound prepared according to another embodiment of the present invention. In FIG. 13A and FIG. 13B , the X-axis represents the angle at which the light beam is emitted, and the Y-axis represents the size of the crystal. In particular, FIG. 13A is a diagram illustrating the crystal properties of a thin film of a perovskite compound prepared by the process of FIG. 2 , and FIG. 13B is a diagram illustrating the crystal properties of a thin film of a perovskite compound prepared by the process of FIG. 6 . Specifically, FIG. 13A shows the supply of Pb(C 2H 5) 4. Perform the first purge, and supply HI as an X precursor for the first time while the power source for plasma formation is kept on to make PbI 2 is formed on the substrate, a second purge is performed, and methylamine (MA) is supplied as an A precursor to make MAPbI 2 is formed on the substrate, a third purge is performed, and HI as an X precursor is supplied for the second time while the power source for plasma formation is kept on so that MAPbI 3 is formed on the substrate, and the MAPbI prepared by the fourth blow-off 3. Crystal properties of perovskite compounds. FIG. 13B shows the effect of supplying Pb(C) as a precursor of B. 2H 5) 4. Perform the first purge, and supply HI as an X precursor for the first time while the power source for plasma formation is kept on to make PbI 2 is formed on the substrate, a second purge is performed, pyridine is supplied, a third purge is performed, methylamine (MA) as a precursor of A is supplied to make MAPbI 2 is formed on the substrate, the fourth purge is performed, and HI as an X precursor is supplied for the second time while the power source for plasma formation is kept on so that MAPbI 3 is formed on the substrate, and the MAPbI prepared by the fifth blow-off 3. Crystal properties of perovskite compounds. In the case of the perovskite compound prepared according to Figure 13A, the direction (110) as the crystal growth direction is the main peak, but additional peaks are also grown to reduce the characteristics of the crystal growth direction being aligned in one direction, and the characteristics of the amorphous characteristics are presented in the range of 10° to 40°. On the other hand, in the case of the perovskite compound prepared according to FIG. 13B , the crystal growth direction (110) is the main peak and almost no additional peak grows, which means that the characteristic of aligning the crystal growth direction in one direction is improved. In particular, in Figure 13B, a large peak is formed, indicating that a large crystal is formed. When the crystal is formed large in this way, the probability of loss between crystals is low, and the conductivity is excellent. 14A to 14E are schematic cross-sectional views illustrating a method for manufacturing a solar cell according to an embodiment of the present invention. First, as shown in FIG14A , a crystalline solar cell 100 is manufactured. The crystalline solar cell 100 is manufactured by etching one surface and the other surface of a semiconductor substrate 110, such as a wafer, to form a concave-convex structure, doping the one surface of the semiconductor substrate 110 with specific dopants to form a first semiconductor layer 120, and doping the other surface of the semiconductor substrate 110 with specific dopants to form a second semiconductor layer 130. Since the one surface and the other surface of the semiconductor substrate 110 are formed into a concavo-convex structure, the first semiconductor layer 120 and the second semiconductor layer 130 are formed into shapes corresponding to the concavo-convex structures. On the other hand, the figure shows that the one surface and the other surface of the semiconductor substrate 110 are formed into a concave-convex structure, but this is not necessarily limited to this. The one surface of the semiconductor substrate 110 can be formed into a concave-convex structure, and the other surface can be formed into a flat structure. Alternatively, the other surface of the semiconductor substrate 110 can be formed into a concave-convex structure, and the one surface can be formed into a flat structure. In some cases, the one surface and the other surface of the semiconductor substrate 110 can be formed into a flat structure. 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. Although not shown, an I-type semiconductor layer may be additionally formed between the semiconductor substrate 110 and the first semiconductor layer 120 , and between the semiconductor substrate 110 and the second semiconductor layer 130 . Next, as shown in FIG. 14B , a buffer layer 200 is formed on the crystalline solar cell 100 . 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. The buffer layer 200 is provided between the crystalline solar cell 100 and the perovskite solar cell 300 described below, and thus the solar cell according to one embodiment of the present invention has a tandem solar cell structure based on a tunnel junction. It is preferable that the buffer layer 200 includes a material for allowing 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, the material may be doped with an n-type or p-type dopant. 14C , the perovskite solar cell 300 is formed on the buffer layer 200. 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. The perovskite solar cell 300 may include a first conductive charge transfer layer provided on the buffer layer 200 , a light absorbing layer provided on the first conductive charge transfer layer, and a second conductive charge transfer layer provided on the light absorbing layer. 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. The electron transport layer may include an N-type organic material such as bathocuproine (BCP), C60 or phenyl-C61-butyric acid methyl ester (PCBM), or an organic material known to those skilled in the art such as ZnO, c-TiO 2 / mp-TiO 2. SnO 2 or IZO and other N-type metal oxides, as well as compounds containing various N-type organic or inorganic materials. The hole transport layer may include those known to those skilled in the art, such as 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-MeO-TAD), 2,2',7,7'-tetrakis(N,N-dimethylphenyl)aminospirobifluorene (Spiro-TTB), polyaniline, polyphenol, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate, and the like. sulfonate, PEDOT-PSS), polytriarylamine (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], PTAA) and poly(3-hexylthiophene-2,5-diyl), P3HT and other P-type organic materials, various P-type metal oxides such as Ni oxide, Mo oxide, V oxide, W oxide or Cu oxide known to those skilled in the art, and compounds containing various P-type organic or inorganic materials. The light absorbing layer includes a thin film of the aforementioned perovskite compound, and thus repeated description of the light absorbing layer will be omitted. Next, as shown in FIG. 14D , 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 . Because the first electrode 400 is formed on the incident surface for sunlight to enter, the first electrode 400 is patterned into a predetermined shape. The second electrode 500 can also be patterned into a predetermined shape to allow reflected sunlight to enter the solar cell, but the invention is not limited thereto. 14E , a passivation layer 600 is formed on the first electrode 400. In this case, a portion of the passivation layer 600 is etched to expose the first electrode 400. Since the perovskite solar cell 300 is formed into a concave-convex structure, the passivation layer 600 may be formed into a concave-convex structure. The passivation layer 600 may be made of, for example, SiO, SiON, SiN, Al 2O In particular, the passivation layer 600 may be made of polydimethylsiloxane, and when polydimethylsiloxane is formed on the perovskite solar cell 300, a micro-pyramid concave-convex structure may be obtained. While embodiments of the present invention have been described in detail above with reference to the relevant drawings, the present invention is not limited to these embodiments and may 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 exemplary and non-restrictive in every respect. It should be understood that the scope of the present invention is defined by the following claims, not the embodiments, and that the scope and meaning of the claims, as well as all variations and modifications derived from concepts equivalent to the claims, are encompassed within the scope of the present invention. 100: crystalline solar cell 110: semiconductor substrate 120: first semiconductor layer 130: second semiconductor layer 200: buffer layer 300: perovskite solar cell 400: first electrode 500: second electrode 600: passivation layer S10, S20, S30, S40, S43, S46, S50, S60, S70, S80: steps FIG1 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to one embodiment of the present invention. FIG2 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. FIG3 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. FIG4 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. FIG5 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. FIG6 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. FIG7 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. FIG8 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. FIG9 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. FIG10 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. FIG11 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. FIG12 is a flow chart illustrating a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. Figure 13A is a diagram illustrating the crystal properties of a thin film of a perovskite compound prepared according to one embodiment of the present invention, and Figure 13B is a diagram illustrating the crystal properties of a thin film of a perovskite compound prepared according to another embodiment of the present invention. Figures 14A to 14E are schematic cross-sectional views illustrating a method for manufacturing a solar cell according to one embodiment of the present invention. S10~S60: Steps

Claims

1. A method for forming a thin film of a perovskite compound, comprising: a process of supplying a B precursor to a cavity; a process of first supplying an X precursor to the cavity; and a process of supplying an A precursor to the cavity, wherein the B precursor comprises an organometallic compound comprising a divalent positive ion, the X precursor comprises a hydrogen halide, and the A precursor comprises at least one compound selected from the group consisting of an amino compound and an amidine compound, and wherein the process of supplying the A precursor is performed after the process of supplying the B precursor and the process of first supplying the X precursor.

2. The method of forming a thin film of a perovskite compound as claimed in claim 1, wherein the process of supplying the B precursor includes a process of adsorbing the B precursor onto a substrate, and wherein the process of first supplying the X precursor includes reacting the B precursor with the X precursor to form an intermediate material made of a BXn (n < 3) compound on the substrate, wherein the process of supplying the A precursor includes reacting the intermediate material made of the BXn (n < 3) compound with the A precursor to form an ABXn (n < 3) compound on the substrate, and wherein the A comprises at least one monovalent organic cation selected from a group consisting of monovalent organic cations of the amine compound and monovalent organic cations of the amidine compound, the B comprises a divalent cation, and the X comprises a halogen compound.

3. The method of forming a thin film of a perovskite compound as claimed in claim 1 further includes a purging process performed during at least one of the process of supplying the B precursor and the process of first supplying the X precursor, the process of first supplying the X precursor and the process of supplying the A precursor, and the period after the process of supplying the A precursor.

4. The method for forming a thin film of a perovskite compound as described in claim 1 further includes a process of supplying the X precursor to the cavity a second time after the process of supplying the A precursor.

5. The method of forming a thin film of a perovskite compound as claimed in claim 4, wherein the process of supplying the X precursor to the cavity for the second time includes a process of applying a power source for plasma formation.

6. The method of forming a thin film of a perovskite compound as described in claim 4 or 5, further comprising a blow-off process performed during at least one of the following periods: the period between the process of supplying the B precursor and the process of first supplying the X precursor, the period between the process of first supplying the X precursor and the process of supplying the A precursor, the period between the process of supplying the A precursor and the process of second supplying the X precursor, and the period after the process of second supplying the X precursor.

7. A method for forming a thin film of a perovskite compound as described in claim 4 or 5, wherein the process of supplying the B precursor includes a process of adsorbing the B precursor onto a substrate, and wherein the process of first supplying the X precursor includes reacting the B precursor with the X precursor to form a primary intermediate material made of a BXn (n < 3) compound on the substrate, wherein the process of supplying the A precursor includes reacting the primary intermediate material made of the BXn (n < 3) compound with the A precursor to form a primary intermediate material made of an ABXn (n < 3) compound on the substrate. A process for forming a secondary intermediate material made of (n<3) compound on the substrate, wherein the process for supplying the X precursor for the second time includes a process for forming the ABX3 compound on the substrate by reacting the secondary intermediate material made of the ABXn (n<3) compound with the X precursor, and wherein A includes at least one monovalent organic cation selected from a group consisting of monovalent organic cations of the amino compound and monovalent organic cations of the amidoyl compound, B includes a divalent cation, and X includes a halogen compound.

8. The method of forming a thin film of a perovskite compound as claimed in any one of claims 1 to 5, further comprising, in the process of supplying a precursor B, a precursor C being supplied to the cavity, wherein the precursor C comprises at least one alkali metal-based compound.

9. A method for forming a thin film of a perovskite compound as claimed in claim 8, wherein the process of supplying the B precursor and the C precursor includes a process of adsorbing the B precursor and the C precursor onto a substrate, and wherein the process of first supplying the X precursor includes forming an intermediate material made of a CBXn (n < 3) compound on the substrate by reacting the B precursor and the C precursor with the X precursor, wherein the process of supplying the A precursor includes forming a CABXn (n < 3) compound on the substrate by reacting the intermediate material made of the CBXn (n < 3) compound with the A precursor, and wherein the A comprises at least one monovalent organic cation selected from the group consisting of monovalent organic cations of the amine compound and monovalent organic cations of the amidoyl compound, the B comprises a divalent cation, the C comprises an alkali metal, and the X comprises a halogen compound.

10. The method of forming a thin film of a perovskite compound as claimed in any one of claims 1 to 5, further comprising a process of supplying a crystal control material into the cavity between the process of first supplying the X precursor and the process of supplying the A precursor.

11. The method of forming a thin film of a perovskite compound as described in claim 10, wherein the crystal control material comprises pyridine or a pyridine derivative.

12. The method of forming a thin film of a perovskite compound as claimed in claim 1, wherein the process of first supplying the X precursor into the cavity includes a process of applying a power source for plasma formation.

13. A method for forming a thin film of a perovskite compound, comprising: a process of supplying a B precursor and a C precursor into a cavity; and a process of first supplying an X precursor into the cavity, wherein the B precursor comprises an organometallic compound comprising a divalent positive ion, the C precursor comprises at least one alkali metal-based compound, and the X precursor comprises hydrogen halide, wherein the process of first supplying the X precursor is performed after the process of supplying the B precursor and the C precursor.

14. A method of forming a thin film of a perovskite compound, comprising: a process of supplying a C precursor to a cavity; a process of supplying a B precursor to the cavity; and a process of first supplying an X precursor to the cavity, wherein the B precursor comprises an organometallic compound comprising a divalent positive ion, the C precursor comprises at least one alkali metal-based compound, and the X precursor comprises hydrogen halide, wherein the process of supplying the C precursor is performed prior to the process of supplying the B precursor and the process of first supplying the X precursor.

15. A method of manufacturing a solar cell, comprising: forming a crystalline solar cell; forming a buffer layer on the crystalline solar cell; forming a perovskite solar cell on the buffer layer; forming a first electrode on the perovskite solar cell and forming a second electrode on the crystalline solar cell, wherein forming the perovskite solar cell comprises the method of forming a thin film of a perovskite compound as described in claim 1.

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