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

Abstract

The present invention provides a method for forming a thin film of a perovskite compound, and a method for manufacturing a solar cell using the same, comprising the steps of: supplying a B precursor into a chamber; primarily supplying an X precursor while maintaining a power source for plasma generation in an on state in the chamber; and supplying an A precursor into the chamber, wherein the B precursor comprises an organometallic compound containing a divalent cation, the X precursor comprises a hydrogen halide, and the A precursor comprises at least one compound selected from an amine compound and an amidine compound, and the step of supplying the A precursor is performed after the step of supplying the B precursor and the step of primarily supplying the X precursor.

Description

[Technical Field]

[0001] 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. [Background technology]

[0002] Conventionally, a wet process has been mainly used to manufacture solar cells using perovskite compounds, in which a perovskite compound is dissolved in a predetermined solvent and then coated onto a substrate using methods such as spin coating, spray coating, or slot die.

[0003] Such a wet process poses no problems when applying a perovskite compound to a substrate with a flat surface. However, when applying a perovskite compound to a crystalline silicon substrate with irregularities in a pyramidal structure to form a tandem solar cell, the step coverage is poor and it is not easy to form a thin film of uniform thickness. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention has been devised to solve the above-mentioned problems of the related art, and an object of the present invention is to provide a method for forming a thin film of a perovskite compound using a vapor deposition process, particularly atomic layer deposition, and a method for manufacturing a solar cell using the same. [Means for solving the problem]

[0005] In order to achieve the above object, the present invention provides a method for forming a thin film of a perovskite compound, comprising the steps of supplying a B precursor into a chamber, primarily supplying an X precursor into the chamber, and supplying an A precursor into the chamber, wherein the B precursor comprises an organometallic compound containing a divalent cation, the X precursor comprises a hydrogen halide, and the A precursor comprises at least one compound selected from an amine compound and an amidine compound, and the step of supplying the A precursor is performed after the steps of supplying the B precursor and primarily supplying the X precursor.

[0006] The step of supplying the B precursor may include a step of adsorbing the B precursor on a substrate; the step of primarily supplying the X precursor may include a step of reacting the B precursor with the X precursor to form an intermediate substance consisting of a BXn (n≦3) compound on the substrate; the step of supplying the A precursor may include a step of reacting the intermediate substance consisting of the BXn (n≦3) compound with the A precursor to form an ABXn (n≦3) compound; A may be at least one monovalent organic cation selected from the group consisting of monovalent organic cations of the amine-based compounds and monovalent organic cations of the amidine-based compounds; B may be the divalent cation; and X may be a halogen compound.

[0007] A purge step may be further performed at least one between the step of supplying the B precursor and the step of primarily supplying the X precursor, between the step of primarily supplying the X precursor and the step of supplying the A precursor, and after the step of supplying the A precursor.

[0008] The method may further include a step of secondarily supplying an X precursor into the chamber after the step of supplying the A precursor.

[0009] The step of secondarily supplying the X precursor into the chamber may include the step of applying a power source for plasma formation.

[0010] A purge step may be further performed at least one of between the step of supplying the B precursor and the step of primarily supplying the X precursor, between the step of primarily supplying the X precursor and the step of supplying the A precursor, between the step of supplying the A precursor and the step of secondarily supplying the X precursor, and after the step of secondarily supplying the X precursor.

[0011] The step of supplying the B precursor includes a step of adsorbing the B precursor on a substrate; the step of primarily supplying the X precursor includes a step of reacting the B precursor with the X precursor to form a primary intermediate of a BXn (n<3) compound on the substrate; the step of supplying the A precursor includes a step of reacting the primary intermediate of the BXn (n<3) compound with the A precursor to form a secondary intermediate of an ABXn (n<3) compound; and the step of secondarily supplying the X precursor includes a step of reacting the secondary intermediate of the ABXn (n<3) compound with the X precursor to form an ABX3 compound on the substrate; A may be at least one monovalent organic cation selected from the group consisting of monovalent organic cations of amine-based compounds and monovalent organic cations of amidine-based compounds; B may be the divalent cation; and X may be a halogen compound.

[0012] During the step of supplying the B precursor, a C precursor may be supplied into the chamber, and the C precursor may comprise at least one alkali metal-based compound.

[0013] The step of simultaneously supplying the B precursor and the C precursor comprises a step of adsorbing the B precursor and the C precursor on a substrate; the step of primarily supplying the X precursor comprises a step of reacting the B precursor, the C precursor, and the X precursor to form an intermediate substance comprising a CBXn (n≦3) compound on the substrate; the step of supplying the A precursor comprises a step of reacting the intermediate substance comprising the CBXn (n≦3) compound with the A precursor to form a CABXn (n≦3) compound; A may comprise at least one monovalent organic cation selected from the monovalent organic cations of the amine-based compounds and the monovalent organic cations of the amidine-based compounds; B may comprise a divalent cation; C may comprise an alkali metal; and X may comprise a halogen compound.

[0014] The method may further include the step of supplying a crystallinity controlling material into the chamber between the step of primarily supplying the X precursor and the step of supplying the A precursor.

[0015] The crystallinity control substance may include pyridine or a pyridine derivative.

[0016] The step of primarily supplying the X precursor into the chamber may include the step of applying a power source for plasma formation.

[0017] The present invention provides a method for forming a thin film of a perovskite compound, comprising the steps of supplying a B precursor and a C precursor into a chamber, and primarily supplying an X precursor into the chamber, wherein the B precursor comprises an organometallic compound containing a divalent cation, the X precursor comprises a hydrogen halide, the C precursor comprises at least one alkali metal compound, and the X precursor comprises a hydrogen halide, and the step of primarily supplying the X precursor is performed after the steps of supplying the B precursor and supplying the C precursor.

[0018] The present invention also provides a method for forming a thin film of a perovskite compound, comprising the steps of supplying a C precursor into a chamber, supplying a B precursor into the chamber, and primarily supplying an X precursor into the chamber, wherein the B precursor comprises an organometallic compound containing a divalent cation, the X precursor comprises a hydrogen halide, the C precursor comprises at least one alkali metal compound, and the X precursor comprises a hydrogen halide, and the step of supplying the C precursor is performed before the step of supplying the B precursor and the step of primarily supplying the X precursor.

[0019] The present invention also provides a method for manufacturing a solar cell, comprising the steps of forming a crystalline solar cell, forming a buffer layer on the crystalline solar cell, forming a perovskite solar cell on the buffer layer, and forming a first electrode on the perovskite solar cell and a second electrode on the crystalline solar cell, wherein the step of forming the perovskite solar cell includes the method for forming a thin film of a perovskite compound described above. [Effects of the Invention]

[0020] According to the present invention as described above, the following effects are obtained.

[0021] According to one embodiment of the present invention, a perovskite compound is formed by atomic layer deposition, so that a tandem solar cell can be easily formed by coating the perovskite compound on a crystalline silicon substrate having an uneven surface.

[0022] According to one embodiment of the present invention, the A precursor supplying step is performed after the B precursor supplying step and the X precursor supplying step, thereby easily producing the ABX3 perovskite compound.

[0023] According to one embodiment of the present invention, the A precursor supplying process is performed after the BXn (n≦3) intermediate is formed, so that the A compound in the A precursor is not exposed to plasma, and the BXn (n≦3) intermediate and the A precursor can react without breaking the chemical bond of the A compound.

[0024] According to one embodiment of the present invention, the X precursor is first 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 a thin film of a final ABX3 perovskite compound, thereby allowing for more flexible adjustment of process conditions within a vacuum chamber.

[0025] According to one embodiment of the present invention, when a power source for plasma generation is maintained in an off state during the process of secondarily supplying the X precursor, it is possible to maximally prevent the chemical bond of the A compound in the secondary intermediate material composed of the ABXn (n<3) compound from being broken. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a flowchart of a process for forming a thin film of a perovskite compound according to an embodiment of the present invention. [Figure 2] 1 is a flowchart of a process for forming a thin film of a perovskite compound according to another embodiment of the present invention. [Figure 3] 1 is a flowchart of a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention. [Figure 4] 1 is a flowchart of a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention. [Figure 5] 1 is a flowchart of a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention. [Figure 6] 1 is a flowchart of a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention. [Figure 7]1 is a flowchart of a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention. [Figure 8] 1 is a flowchart of a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention. [Figure 9] 1 is a flowchart of a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention. [Figure 10] 1 is a flowchart of a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention. [Figure 11] 1 is a flowchart of a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention. [Figure 12] 1 is a flowchart of a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention. [Figure 13A] 1 is a graph showing the crystal properties of a thin film of a perovskite compound produced according to an embodiment of the present invention. [Figure 13B] 10 is a graph showing the crystal properties of a thin film of a perovskite compound produced according to another embodiment of the present invention. [Figure 14A] 1A to 1C are cross-sectional views showing steps in a method for manufacturing a solar cell according to an embodiment of the present invention. [Figure 14B] 1A to 1C are cross-sectional views showing steps in a method for manufacturing a solar cell according to an embodiment of the present invention. [Figure 14C] 1A to 1C are cross-sectional views showing steps in a method for manufacturing a solar cell according to an embodiment of the present invention. [Figure 14D] 1A to 1C are cross-sectional views showing steps in a method for manufacturing a solar cell according to an embodiment of the present invention. [Figure 14E] 1A to 1C are cross-sectional views showing steps in a method for manufacturing a solar cell according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] The advantages and features of the present invention, as well as methods for achieving them, will become more apparent from the following detailed description of the embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be embodied in various different forms. These embodiments are provided solely to ensure that the disclosure of the present invention is complete and to fully convey the scope of the invention to those skilled in the art. The present invention is defined only by the scope of the claims.

[0028] The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for illustrating the embodiments of the present invention are merely examples, and the present invention is not limited to the details shown in the drawings. The same reference numerals refer to the same elements throughout the specification. In addition, if a detailed description of related prior art is deemed to unnecessarily obscure the gist of the present invention, the detailed description will be omitted. When "comprises," "has," "consists of," etc. are used in the description of the present invention, other parts may be added unless "only" is used. When an element is expressed in the singular, it also includes the plural unless otherwise explicitly stated.

[0029] When interpreting elements, they are interpreted as including a margin of error unless otherwise expressly stated.

[0030] In the case of a description of a positional relationship, for example, when the positional relationship of two parts is described using "above," "on top," "below," or "beside," one or more other parts may be located between the two parts, unless the words "immediately" or "directly" are used.

[0031] When describing a temporal relationship, for example, when the temporal precedence relationship is described using "after," "following," "next to," or "before," it can also include cases where the relationship is not consecutive, unless the words "immediately" or "directly" are used.

[0032] Although terms such as "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another. Therefore, a first component referred to below may also be a second component within the technical concept of the present invention.

[0033] The features of the various embodiments of the present invention may be partially or fully combined or combined with one another, and may be technically interlocked and driven in various ways, and each embodiment may be implemented independently of the others or may be implemented together in a linked relationship.

[0034] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0035] FIG. 1 is a flowchart showing a process for forming a thin film of a perovskite compound according to one embodiment of the present invention.

[0036] As can be seen from FIG. 1, a thin film of a perovskite compound (ABX3) according to an embodiment of the present invention can be formed through an atomic layer deposition (ALD) process in a vacuum chamber. Specifically, the process includes a step of supplying a B precursor (S10), a first purge process (S20), a step of supplying an X precursor while maintaining a power source for generating plasma in an on state (S30), a second purge process (S40), a step of supplying an A precursor (S50), and a third purge process (S60).

[0037] The step (S10) of supplying the B precursor includes a step of supplying the B precursor onto the substrate in a state in which the substrate is loaded in a vacuum chamber, and causing the B precursor to be adsorbed onto the substrate.

[0038] The B precursor can consist of an organometallic compound containing a divalent cation, and the B can consist of the divalent cation.

[0039] The organometallic compound containing a divalent cation can include a metal selected from the group consisting of Pb, Sn, Ge, Sb, Bi, and Ba.

[0040] Specifically, the organometallic compound containing a divalent cation has the chemical formula shown in Chemical Formula 1 below:

[0041] [ka]

[0042] (In the formula, R 1 ~R 12 are each independently hydrogen or an alkyl group, and X is selected from the group consisting of Pb, Sn, Ge, Sb, Bi, and Ba.

[0043] Alternatively, the organometallic compound containing a divalent cation may be Pb(CH3)4, Pb(C2H5)4, Pb(SCN)2, (C2H5)3PbOCH2C(CH3)3, Pb(C 11 H 19 O2)2, Pb((CH3)3C-COCHCO-C(CH3)3)2, Pb((C6H5)2PCH2P(C6H5)2)2, Pb(N(CH3)2C(CH3)2OH)2 and C 12 H 28 N2O2Pb.

[0044] The first purge step (S20) may include a step of supplying a first purge gas into the vacuum chamber to remove the B precursor remaining on the substrate without being adsorbed thereon.

[0045] The step (S30) of supplying an X precursor while maintaining the power source for plasma generation in an on state may include a step 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 an intermediate material made of a BX3 compound on the substrate.

[0046] The X precursor may be a hydrogen halide, where X is 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 generation is maintained in an off state rather than an on state. The power source for plasma generation may be turned on only for a portion of the period during which the X precursor is supplied.

[0047] The second purge step (S40) may include supplying a second purge gas into the vacuum chamber to remove the X precursor remaining on the substrate without reacting. The second purge gas may be the same as the first purge gas, but may be different in some cases.

[0048] The step (S50) of supplying the A precursor can include a step of supplying the A precursor into the vacuum chamber, reacting the A precursor with the BX3 compound formed on the substrate, and forming a thin film of a perovskite compound made of an ABX3 compound on the substrate.

[0049] The A precursor may be composed of at least one compound selected from an amine compound and an amidine compound. A may be composed of a monovalent organic cation of the amine compound, a monovalent organic cation of the amidine compound, or a monovalent organic cation of the amine compound and a monovalent organic cation of the amidine compound. A may have a structure in which the monovalent organic cation of the amine compound is contained in a ratio x and the monovalent organic cation of the amidine compound is contained in a ratio y. Here, x and y are each greater than 0, and x + y = 1.

[0050] The amine-based compound may be selected from the group consisting of methylamine, ethylamine, and phenethylamine, and the amidine-based compound may be formamidine.

[0051] The third purge step (S60) may include supplying a third purge gas into the vacuum chamber to remove the A precursor remaining on the substrate without reacting. The third purge gas may be the same as the first purge gas or the second purge gas, but may be different in some cases.

[0052] The A precursor, the B precursor, and the X precursor are composed of substances that vaporize at a temperature ranging from room temperature to 200° C., preferably from 50° C. to 150° C. This makes it possible to carry out the process of producing the ABX3 perovskite compound through an atomic layer deposition process at a temperature of 200° C. or lower, preferably 150° C. or lower, and prevents organic substances in the finally obtained ABX3 compound from decomposing during the atomic layer deposition process.

[0053] According to one embodiment of the present invention, the A precursor supplying step (S50) is performed after the B precursor supplying step (S10) and the X precursor supplying step (S30), so that an intermediate material made of a BX3 compound is first formed on the substrate, and then the BX3 compound and the A precursor are reacted to easily produce the ABX3 perovskite compound.

[0054] If the A precursor supplying step (S50) is performed before the B precursor supplying step (S10), and an intermediate material consisting of the AX3 compound is first formed on the substrate, and then the AX3 compound and the B precursor are reacted, the ABX3 perovskite compound cannot be easily produced finally, because the reaction between the AX3 compound and the B precursor does not proceed well.

[0055] Furthermore, if the A precursor supply step (S50) is performed before the B precursor supply step (S10) and the X precursor supply step (S30) is performed while the power source for plasma generation is kept on, the chemical bonds of the A compound in the A precursor, which is made of an organic substance, are broken by the plasma, making it difficult to easily obtain the AX3 intermediate material, and ultimately making it difficult to easily produce the ABX3 perovskite compound.

[0056] In contrast, according to one embodiment of the present invention, the A precursor supplying step (S50) is performed after the BX3 intermediate is formed. This prevents the A compound in the A precursor from being exposed to plasma, and the BX3 intermediate reacts with the A precursor without breaking the chemical bonds of the A compound, thereby easily producing the ABX3 perovskite compound.

[0057] FIG. 2 is a flow chart of a process for forming a thin film of a perovskite compound according to another embodiment of the present invention.

[0058] As can be seen from FIG. 2, a thin film of the perovskite compound (ABX3) according to another embodiment of the present invention can be formed through an atomic layer deposition process in a vacuum chamber. Specifically, the thin film can be formed through a step of supplying a B precursor (S10), a first purge step (S20), a step of primarily supplying an X precursor while maintaining a power source for generating plasma in an on state (S30), a second purge step (S40), a step of supplying an A precursor (S50), a third purge step (S60), a step of secondarily supplying an X precursor while maintaining the plasma in an on or off state (S70), and a fourth purge step (80).

[0059] The B precursor supplying step (S10) and the first purging step (S20) are the same as those described above with reference to FIG. 1, and therefore, a repeated description will be omitted.

[0060] The step (S30) of primarily supplying an X precursor while maintaining the power source for plasma generation in an on state may include a step of supplying the X precursor into the vacuum chamber, reacting the B precursor adsorbed on the substrate with the supplied X precursor, and forming a primary intermediate material composed of a BXn (n<3) compound on the substrate.

[0061] The X precursor and X compound are the same as those in FIG. 1, and therefore a repeated explanation will be omitted.

[0062] The second purge step (S40) is also the same as that shown in FIG. 1, and therefore a repeated explanation will be omitted.

[0063] The step (S50) of supplying the A precursor may include a step of supplying the A precursor into the vacuum chamber, reacting the A precursor with the BXn (n<3) compound formed on the substrate, and forming a secondary intermediate material composed of an ABXn (n<3) compound on the substrate.

[0064] The A precursor and A compound are the same as those in FIG. 1, and therefore a repeated explanation will be omitted.

[0065] The third purge step (S60) may include supplying a third purge gas into the vacuum chamber to remove the A precursor remaining on the substrate without reacting. The third purge gas may be the same as the first purge gas or the second purge gas, but may be different in some cases.

[0066] The step (S70) of secondarily supplying an X precursor while maintaining the plasma in an on or off state may include a step of supplying the X precursor into the vacuum chamber, reacting the ABXn (n<3) compound formed on the substrate with the secondarily supplied X precursor, and forming a thin film of a perovskite compound made of an ABX3 compound on the substrate.

[0067] The X precursor in the step (S70) of secondarily supplying the X precursor while maintaining the plasma in an on or off state may be the same as or different from the X precursor in the step (S30) of primarily supplying the X precursor while maintaining the power source for plasma generation in an on state.

[0068] The fourth purge process (S80) may include supplying a fourth purge gas into the vacuum chamber to remove any X precursor remaining on the substrate without reacting. The fourth purge gas may be the same as the first purge gas, the second purge gas, or the third purge gas, but may be different in some cases.

[0069] As such, according to another embodiment of the present invention, the X precursor is first 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 a thin film of a final ABX3 perovskite compound, thereby allowing for more flexible adjustment of process conditions within a vacuum chamber.

[0070] Meanwhile, a secondary intermediate material consisting of an ABXn (n<3) compound is formed on the substrate through the step of supplying the A precursor (S50), and since the A compound, which is an organic material, is chemically bonded to the B compound and the X compound, the chemical bond of the A compound is not easily broken even if the power source for plasma generation is kept on during the step of secondarily supplying the X precursor (S70). Therefore, it is possible to keep the power source for plasma generation on during the step of secondarily supplying the X precursor (S70).

[0071] However, in order to prevent the chemical bond of the A compound from being broken in the secondary intermediate material consisting of the ABXn (n<3) compound during the step of secondarily supplying the X precursor (S70), it is preferable to keep the power source for plasma generation in an off state during the step of secondarily supplying the X precursor (S70).

[0072] FIG. 3 is a flowchart showing a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention.

[0073] As can be seen from FIG. 3, a thin film of the perovskite compound (ABX3) according to an embodiment of the present invention can be formed through an atomic layer deposition process in a vacuum chamber. Specifically, the process includes a step of supplying a B precursor and a C precursor (S10), a first purge step (S20), a step of supplying an X precursor while maintaining a power source for generating plasma in an on state (S30), a second purge step (S40), a step of supplying an A precursor (S50), and a third purge step (60).

[0074] The step (S10) of supplying the B precursor and the C precursor includes a step of supplying the B precursor and the C precursor onto the substrate in a state in which the substrate is loaded in a vacuum chamber, and causing the B precursor and the C precursor to be adsorbed onto the substrate.

[0075] The B precursor and the C precursor can be supplied simultaneously.

[0076] The B precursor and B compound are the same as those in FIG. 1, and therefore a repeated explanation will be omitted.

[0077] The C precursor may comprise at least one alkali metal-based compound, and the C compound may comprise at least one of the alkali metals, such as cesium (Cs).

[0078] The alkali metal compound has the following chemical formula:

[0079] [ka]

[0080] (In the formula, R 1 ~R 6are each independently hydrogen or an alkyl group, and Y is an alkali metal.

[0081] According to another embodiment of the present invention, the instability of monovalent organic cations, which are vulnerable to moisture, heat, and plasma, can be compensated for by adding at least one alkali metal-based compound to the reaction mixture, as follows:

[0082] The first purge step (S20) may include a step of supplying a first purge gas into a vacuum chamber to remove the B precursor and the C precursor that are not adsorbed on the substrate and remain on the substrate.

[0083] The step (S30) of supplying an X precursor while maintaining the power source for plasma generation in an on state may include a step of supplying the X precursor into the vacuum chamber, reacting the B precursor and the C precursor adsorbed on the substrate with the supplied X precursor, and forming an intermediate material composed of a CBX3 compound on the substrate.

[0084] The X precursor and the X compound are the same as those shown in FIG.

[0085] The second purge step (S40) is the same as that shown in FIG.

[0086] The step (S50) of supplying the A precursor can include a step of supplying the A precursor into the vacuum chamber, reacting the A precursor with the CBX3 compound formed on the substrate, and forming a thin film of a perovskite compound made of a CABX3 compound on the substrate.

[0087] The A precursor and the A compound are the same as those shown in FIG.

[0088] The CA may have a structure in which the monovalent organic cation of the amine-based compound is contained in a ratio x, the monovalent organic cation of the amidine-based compound is contained in a ratio y, and the monovalent cation of the alkali metal is contained in a ratio z, where x, y, and z are each greater than 0, and x + y + z = 1.

[0089] The third purge step (S60) may include supplying a third purge gas into the vacuum chamber to remove the A precursor remaining on the substrate without reacting. The third purge gas may be the same as the first purge gas or the second purge gas, but may be different in some cases.

[0090] FIG. 4 is a flowchart of a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention.

[0091] As can be seen from FIG. 4, a thin film of the perovskite compound (ABX3) according to another embodiment of the present invention can be formed through an atomic layer deposition process in a vacuum chamber. Specifically, the thin film can be formed through a step of supplying a B precursor and a C precursor (S10), a first purge step (S20), a step of primarily supplying an X precursor while maintaining a power source for generating plasma in an on state (S30), a second purge step (S40), a step of supplying an A precursor (S50), a third purge step (S60), a step of secondarily supplying an X precursor while maintaining the plasma in an on state or off state (S70), and a fourth purge step (S80).

[0092] The step (S10) of supplying the B precursor and the C precursor and the first purging step (S20) are the same as those in FIG. 3 described above, and therefore, repeated explanations will be omitted.

[0093] The step (S30) of primarily supplying an X precursor while maintaining the power source for plasma generation in an on state may include a step of supplying the X precursor into the vacuum chamber, reacting the supplied X precursor with the B precursor and C precursor adsorbed on the substrate, and forming a primary intermediate composed of a CBXn (n<3) compound on the substrate.

[0094] The X precursor and X compound are the same as those in FIG. 3, and therefore a repeated description will be omitted.

[0095] The second purge step (S40) is also the same as that shown in FIG. 3, and therefore a repeated explanation will be omitted.

[0096] The step (S50) of supplying the A precursor may include a step of supplying the A precursor into the vacuum chamber and reacting the A precursor with the CBXn (n<3) compound formed on the substrate to form a secondary intermediate material composed of a CABXn (n<3) compound on the substrate.

[0097] The A precursor and A compound are the same as those in FIG. 3, and therefore a repeated explanation will be omitted.

[0098] The third purge step (S60) may include supplying a third purge gas into the vacuum chamber to remove the A precursor remaining on the substrate without reacting. The third purge gas may be the same as the first purge gas or the second purge gas, but may be different in some cases.

[0099] The step (S70) of secondarily supplying an X precursor while maintaining the plasma in an on or off state may include a step of supplying the X precursor into the vacuum chamber, reacting the CABXn (n<3) compound formed on the substrate with the secondarily supplied X precursor, and forming a thin film of a perovskite compound made of a CABX3 compound on the substrate.

[0100] The X precursor in the step (S70) of secondarily supplying the X precursor while maintaining the plasma in an on or off state may be the same as or different from the X precursor in the step (S30) of primarily supplying the X precursor while maintaining the power source for plasma generation in an on state.

[0101] The fourth purge process (S80) may include supplying a fourth purge gas into the vacuum chamber to remove any X precursor remaining on the substrate without reacting. The fourth purge gas may be the same as the first purge gas, the second purge gas, or the third purge gas, but may be different in some cases.

[0102] As such, according to another embodiment of the present invention, the X precursor is first supplied 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 secondarily supplied to form a thin film of a final CABX3 perovskite compound, thereby allowing for more flexible adjustment of process conditions within a vacuum chamber.

[0103] Meanwhile, a secondary intermediate material consisting of a CABXn (n<3) compound is formed on the substrate through the step of supplying the A precursor (S50), and since the A compound, which is an organic material, is chemically bonded to the C compound, the B compound, and the X compound, the chemical bonds of the A compound are not easily broken even if the power source for plasma generation is kept on during the step of secondarily supplying the X precursor (S70). Therefore, it is possible to keep the power source for plasma generation on during the step of secondarily supplying the X precursor (S70).

[0104] However, in order to prevent the chemical bond of the A compound from being broken in the secondary intermediate material consisting of the CABXn (n<3) compound during the step of secondarily supplying the X precursor (S70), it may be preferable to keep the power source for plasma generation in an off state during the step of secondarily supplying the X precursor (S70).

[0105] FIG. 5 is a flowchart of a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention.

[0106] FIG. 5 differs from FIG. 1 in that a pyridine supply step (S43) and a third purge step (S46) are further performed between the second purge step (S40) and the A precursor supply step (S50).

[0107] According to another embodiment of the present invention, by supplying pyridine or a pyridine derivative to an intermediate material made of a BX3 compound and then supplying an A precursor, the crystalline properties of the final perovskite compound made of an ABX3 compound can be improved. In the following description, pyridine or a pyridine derivative will be referred to as pyridine.

[0108] The pyridine derivative may include, but is not necessarily limited to, 4-methylpyridine or 4-tert-butylpyridine.

[0109] In addition to pyridine, a crystal growth regulator or growth regulator for the perovskite compound made of ABX3 compound can be added. The crystal growth regulator or growth regulator can improve the stability of the crystal by removing dangling bonds in the crystal through a passivation effect.

[0110] 5, the third purge process (S46) may include a process of supplying a third purge gas into the vacuum chamber to remove pyridine or a pyridine derivative remaining on the substrate. Meanwhile, in FIG. 5, since the third purge process (S46) is added, the purge process performed after the A precursor supply process (S50) becomes a fourth purge process (S60).

[0111] FIG. 6 is a flowchart of a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention.

[0112] 6 differs from the above-described FIG. 2 in that a pyridine supplying step (S43) and a third purge step (S46) are further performed between the second purge step (S40) and the A precursor supplying step (S50). In FIG. 6, the third purge step (S46) may include a step of supplying a third purge gas into the vacuum chamber to remove the pyridine remaining on the substrate.

[0113] On the other hand, in FIG. 6, a third purge step (S46) is added, so the purge step performed after the A precursor supply step (S50) becomes a fourth purge step (S60), and the purge step performed after the step (S70) of secondarily supplying the X precursor while maintaining the plasma in an on or off state becomes a fifth purge step (S80).

[0114] FIG. 7 is a flowchart of a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention.

[0115] 7 differs from the above-described FIG. 3 in that a pyridine supplying step (S43) and a third purge step (S46) are further performed between the second purge step (S40) and the A precursor supplying step (S50). In FIG. 7, the third purge step (S46) may include a step of supplying a third purge gas into the vacuum chamber to remove pyridine remaining on the substrate.

[0116] On the other hand, in FIG. 7, a third purge step (S46) is added, and therefore the purge step performed after the A precursor supply step (S50) becomes a fourth purge step (S60).

[0117] FIG. 8 is a flowchart of a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention.

[0118] 8 differs from the above-described FIG. 4 in that a pyridine supplying step (S43) and a third purge step (S46) are further performed between the second purge step (S40) and the A precursor supplying step (S50). In FIG. 8, the third purge step (S46) may include a step of supplying a third purge gas into the vacuum chamber to remove pyridine remaining on the substrate.

[0119] On the other hand, in FIG. 8, a third purge step (S46) is added, so the purge step performed after the A precursor supply step (S50) becomes a fourth purge step (S60), and the purge step performed after the step (S70) of secondarily supplying the X precursor while maintaining the plasma in an on or off state becomes a fifth purge step (S80).

[0120] FIG. 9 is a flowchart of a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention.

[0121] As can be seen from FIG. 9, a thin film of the perovskite compound (ABX3) according to another embodiment of the present invention can be formed through an atomic layer deposition process in a vacuum chamber, specifically through a step of supplying a B precursor and a C precursor (S10), a first purging step (S20), a step of supplying an X precursor while maintaining a power source for plasma generation in an on state (S30), and a second purging step (S40).

[0122] Since each step is the same as that described above, repeated explanations will be omitted, and the same applies to the following examples.

[0123] FIG. 10 is a flowchart of a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention.

[0124] As can be seen from FIG. 10, a thin film of the perovskite compound (ABX3) according to another embodiment of the present invention can be formed through an atomic layer deposition process in a vacuum chamber, specifically through a step of supplying a C precursor (S10), a first purge step (S20), a step of supplying a B precursor (S30), a second purge step (S40), a step of supplying an X precursor while maintaining a power source for plasma generation in an on state (S50), and a third purge step (S60).

[0125] FIG. 11 is a flowchart showing a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention.

[0126] As can be seen from FIG. 11, a thin film of the perovskite compound (ABX3) according to another embodiment of the present invention can be formed through an atomic layer deposition process in a vacuum chamber, specifically through a step of supplying a B precursor and a C precursor (S10), a first purging step (S20), a step of supplying an X precursor while maintaining a power source for plasma generation in an on state (S30), a second purging step (S40), a step of supplying pyridine (S50), and a third purging step (S60).

[0127] FIG. 12 is a flowchart showing a process for forming a thin film of a perovskite compound according to still another embodiment of the present invention.

[0128] As can be seen from FIG. 12, a thin film of the perovskite compound (ABX3) according to another embodiment of the present invention can be formed through an atomic layer deposition process in a vacuum chamber, specifically through a step of supplying a C precursor (S10), a first purge step (S20), a step of supplying a B precursor (S30), a second purge step (S40), a step of supplying an X precursor while maintaining a power source for plasma generation in an on state (S50), a third purge step (S60), a step of supplying pyridine (S70), and a fourth purge step (S80).

[0129] In the above-described embodiments of FIGS. 9 to 12, a step of supplying an X precursor while maintaining the power source for plasma generation in an on or off state after each purge step and a subsequent purge step may be further included.

[0130] FIG. 13A is a graph showing the crystalline characteristics of a thin film of a perovskite compound prepared according to one embodiment of the present invention, and FIG. 13B is a graph showing the crystalline characteristics of a thin film of a perovskite compound prepared according to another embodiment of the present invention.

[0131] In Figures 13A and 13B, the X axis represents the beam irradiation angle, and the Y axis represents the crystal size.

[0132] In particular, FIG. 13A is a graph showing the crystallinity of a thin film of a perovskite compound produced by the process shown in FIG. 2 described above, and FIG. 13B is a graph showing the crystallinity of a thin film of a perovskite compound produced by the process shown in FIG. 6 described above.

[0133] Specifically, FIG. 13A is a graph showing the crystallinity of a perovskite compound made of MAPbI3 prepared through the following processes: supplying Pb(C2H5)4 as a B precursor, performing a first purge, primarily supplying HI as an X precursor while maintaining the power source for plasma generation in an on state to form PbI2 on a substrate, performing a second purge, supplying methylamine (MA) as an A precursor, forming MAPbI2 on the substrate, performing a third purge, secondary supplying HI as an X precursor while maintaining the power source for plasma generation in an on state to form MAPbI3 on ​​the substrate, and then performing a fourth purge.

[0134] FIG. 13b is a graph showing the crystallinity of a perovskite compound made of MAPbI3 prepared through the steps of supplying Pb(C2H5)4 as a B precursor, performing a first purge, primarily supplying HI as an X precursor while maintaining the power source for plasma generation in an on state to form PbI2 on a substrate, performing a second purge, supplying pyridine, performing a third purge, supplying methylamine as an A precursor to form MAPbI2 on the substrate, performing a fourth purge, secondary supplying HI as an X precursor while maintaining the power source for plasma generation in an on state to form MAPbI3 on ​​the substrate, and then performing a fifth purge.

[0135] In the case of the perovskite compound manufactured according to FIG. 13A, the (110) direction, which is the crystal growth direction, is the main peak, but as additional peaks grow, the crystal growth direction tends to be less aligned in one direction, and the compound tends to have crystalline properties in the range of 10 degrees to 40 degrees.

[0136] In the case of the perovskite compound manufactured according to FIG. 13B, the (110) direction, which is the crystal growth direction, grows as the main peak, and there are almost no additional peaks, indicating that the crystal growth direction is excellent in that it is aligned in one direction.

[0137] In particular, in the case of Figure 13B, a large peak is formed, which is due to the large crystals formed. When the crystals are formed in this way, there is little loss between the crystals, resulting in excellent electrical conductivity.

[0138] 14A to 14E are cross-sectional views illustrating steps in a method for manufacturing a solar cell according to one embodiment of the present invention.

[0139] First, as can be seen from FIG. 14A, a crystalline solar cell 100 is manufactured.

[0140] The crystalline solar cell 100 can be manufactured by the process of etching one side and the other side of the semiconductor substrate 110, such as a wafer, to form a rough structure, doping one side of the semiconductor substrate 110 with a predetermined dopant to form a first semiconductor layer 120, and doping the other side of the semiconductor substrate 110 with a predetermined dopant to form a second semiconductor layer 130.

[0141] Since one surface and the other surface of the semiconductor substrate 110 are formed with an uneven structure, the first semiconductor layer 120 and the second semiconductor layer 130 each have a shape corresponding to the uneven structure.

[0142] Meanwhile, although the drawings show a state in which both one side and the other side of the semiconductor substrate 110 are formed with an uneven structure, this is not necessarily limited thereto, and either one side of the semiconductor substrate 110 may be formed with an uneven structure and the other side may be formed with a flat structure. In some cases, both one side and the other side of the semiconductor substrate 110 may be formed with a flat structure.

[0143] The semiconductor substrate 110 may be a P-type or N-type wafer, the first semiconductor layer 120 may be doped with a dopant having a polarity different 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 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.

[0144] Although not shown, an I-type semiconductor layer may be further formed between the semiconductor substrate 110 and the first semiconductor layer 120 and between the semiconductor substrate 110 and the second semiconductor layer 130 .

[0145] Next, as can be seen from FIG. 14B, a buffer layer 200 is formed on the upper surface of the crystalline solar cell 100.

[0146] The buffer layer 200 is formed on the first semiconductor layer 120. Since the first semiconductor layer 120 has an uneven structure, the buffer layer 200 also has an uneven structure.

[0147] The buffer layer 200 is provided between the crystalline solar cell 100 and the perovskite solar cell 300 described below, so that the solar cell according to an embodiment of the present invention has a tandem solar cell structure through a tunnel junction.

[0148] The buffer layer 200 is preferably made of a material that allows long-wavelength light that passes through the perovskite solar cell 300 to be incident without loss on the crystalline solar cell 100. For example, the buffer layer 200 may be made 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.

[0149] 14C, a perovskite solar cell 300 is formed on the buffer layer 200. Since the buffer layer 200 is formed with an uneven structure, the perovskite solar cell 300 can also be formed with an uneven structure.

[0150] 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.

[0151] The first conductive charge transport layer may be an electron transport layer and the second conductive charge transport layer may be a hole transport layer, or the first conductive charge transport layer may be a hole transport layer and the second conductive charge transport layer may be an electron transport layer.

[0152] The electron transport layer may be made of an N-type organic material such as BCP (Bathocuproine), C60, or PCBM (Phenyl-C61-butanoic acid methyl ester), or various N-type metal oxides known in the art such as ZnO, c-TiO2 / mp-TiO2, SnO2, or IZO, in addition to various organic or inorganic materials. The hole transport layer may be made of Spiro-MeO-TAD, Spiro-TTB, polyaniline, polyvinyl alcohol, or poly-3,4-ethylenedioxythiophene. The organic thin film may be composed of various N-type organic materials known in the art, such as phenyl-polystyrene sulfonate (PEDOT-PSS), poly-[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly(3-hexylthiophene-2,5-diyl) (P3HT), etc., or may be composed of various P-type metal oxides known in the art, such as Ni oxide, Mo oxide, V oxide, W oxide, Cu oxide, etc., in addition to various organic or inorganic compounds.

[0153] The light absorbing layer is made of a thin film of the perovskite compound described above, and therefore, a repeated description of the light absorbing layer will be omitted.

[0154] Next, as can be seen from FIG. 14D, a first electrode 400 is formed on the upper surface of the perovskite solar cell 300, and a second electrode 500 is formed on the lower surface of the crystalline solar cell 100.

[0155] The first electrode 400 is formed on an incident surface where sunlight is incident, and is therefore patterned in a predetermined shape. The second electrode 500 is also patterned in a predetermined shape, and can be configured to allow reflected sunlight to enter the solar cell, but is not necessarily limited thereto.

[0156] 14E, a passivation layer 600 is formed on the first electrode 400. A portion of the passivation layer 600 is etched to expose the first electrode 400.

[0157] Since the perovskite solar cell 300 has a concave-convex structure, the passivation layer 600 can also have a concave-convex structure. The passivation layer 600 can be made of various materials such as SiO, SiON, SiN, Al2O3, or MgF. In particular, the passivation layer 600 can be made of polydimethylsiloxane, and when the polydimethylsiloxane is formed on the perovskite solar cell 300, a micropyramid-shaped concave-convex structure can be obtained.

[0158] Although the present invention has been described in detail above with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments and can be embodied in various modifications without departing from the spirit and scope of the present invention. Therefore, the disclosed embodiments are intended to illustrate, rather than limit, the spirit and scope of the present invention, and should not be construed as limiting the scope of the present invention. Therefore, the above-described embodiments should be understood to be illustrative in all respects and not restrictive. The scope of protection of the present invention should be interpreted by the scope of the claims, and all technical concepts within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

Claims

1. providing a B precursor into the chamber; providing a primary supply of an X precursor into the chamber; and providing an A precursor into the chamber; the B precursor is an organometallic compound containing a divalent cation, the X precursor is a hydrogen halide, and the A precursor is at least one compound selected from an amine compound and an amidine compound; A method for forming a thin film of a perovskite compound, characterized in that the step of supplying the A precursor is carried out after the step of supplying the B precursor and the step of primarily supplying the X precursor.

2. the step of supplying the B precursor includes a step of adsorbing the B precursor on a substrate; the step of primarily supplying the X precursor includes a step of reacting the B precursor with the X precursor to form an intermediate substance composed of a BXn (n≦3) compound on the substrate, the step of supplying the A precursor includes a step of reacting the A precursor with an intermediate substance consisting of the BXn (n≦3) compound to form an ABXn (n≦3) compound, 2. The method for forming a thin film of a perovskite compound according to claim 1, wherein A comprises at least one monovalent organic cation selected from the group consisting of monovalent organic cations of the amine-based compound and monovalent organic cations of the amidine-based compound, B comprises the divalent cation, and X comprises a halogen compound.

3. 2. The method for forming a thin film of a perovskite compound according to claim 1, further comprising a purging step being carried out at least one of between the step of supplying the B precursor and the step of primarily supplying the X precursor, between the step of primarily supplying the X precursor and the step of supplying the A precursor, and after the step of supplying the A precursor.

4. 2. The method for forming a thin film of a perovskite compound according to claim 1, further comprising the step of secondarily supplying an X precursor into the chamber after the step of supplying the A precursor.

5. 5. The method for forming a thin film of a perovskite compound according to claim 4, wherein the step of secondarily supplying an X precursor into the chamber includes the step of applying a power source for plasma formation.

6. 5. The method for forming a thin film of a perovskite compound according to claim 4, further comprising carrying out a purging step at least one of between the step of supplying the B precursor and the step of primarily supplying the X precursor, between the step of primarily supplying the X precursor and the step of supplying the A precursor, between the step of supplying the A precursor and the step of secondarily supplying the X precursor, and after the step of secondarily supplying the X precursor.

7. the step of supplying the B precursor includes a step of adsorbing the B precursor on a substrate; the step of primarily supplying the X precursor includes a step of reacting the B precursor with the X precursor to form a primary intermediate substance composed of a BXn (n<3) compound on the substrate; the step of supplying the A precursor includes a step of reacting the primary intermediate substance consisting of the BXn (n<3) compound with the A precursor to form a secondary intermediate substance consisting of an ABXn (n<3) compound, The step of secondarily supplying the X precursor comprises reacting the secondary intermediate material composed of the ABXn (n<3) compound with the X precursor to form ABX on the substrate. ３ forming a compound, 5. The method for forming a thin film of a perovskite compound according to claim 4, wherein A comprises at least one monovalent organic cation selected from the group consisting of monovalent organic cations of the amine-based compound and monovalent organic cations of the amidine-based compound, B comprises the divalent cation, and X comprises a halogen compound.

8. supplying a C precursor into the chamber during the step of supplying the B precursor; 2. The method for forming a thin film of a perovskite compound according to claim 1, wherein the C precursor comprises at least one alkali metal compound.

9. the step of supplying the B precursor and the C precursor includes a step of adsorbing the B precursor and the C precursor on a substrate; the step of primarily supplying the X precursor includes a step of reacting the B precursor, the C precursor, and the X precursor to form an intermediate substance consisting of a CBXn (n≦3) compound on the substrate; the step of supplying the A precursor includes a step of reacting the A precursor with an intermediate substance consisting of the CBXn (n≦3) compound to form a CABXn (n≦3) compound, 9. The method for forming a thin film of a perovskite compound according to claim 8, wherein A comprises at least one monovalent organic cation selected from the group consisting of monovalent organic cations of the amine-based compound and monovalent organic cations of the amidine-based compound, B comprises the divalent cation, C comprises an alkali metal, and X comprises a halogen compound.

10. 2. The method for forming a thin film of a perovskite compound according to claim 1, further comprising the step of supplying a crystallinity control substance into the chamber between the step of primarily supplying the X precursor and the step of supplying the A precursor.

11. 11. The method for forming a thin film of a perovskite compound according to claim 10, wherein the crystallinity controlling substance includes pyridine or a pyridine derivative.

12. 2. The method for forming a thin film of a perovskite compound according to claim 1, wherein the step of primarily supplying an X precursor into the chamber includes the step of applying a power source for plasma formation.

13. providing a B precursor and a C precursor into the chamber; and a step of primarily supplying an X precursor into the chamber; the B precursor comprises an organometallic compound containing a divalent cation, and the X precursor comprises a hydrogen halide; the C precursor comprises at least one alkali metal-based compound; the X precursor comprises a hydrogen halide; A method for forming a thin film of a perovskite compound, characterized in that the step of primarily supplying the X precursor is carried out after the step of supplying the B precursor and the step of supplying the C precursor.

14. providing a C precursor into the chamber; providing a B precursor into the chamber; and a step of primarily supplying an X precursor into the chamber; the B precursor comprises an organometallic compound containing a divalent cation, and the X precursor comprises a hydrogen halide; the C precursor comprises at least one alkali metal-based compound; the X precursor comprises a hydrogen halide; A method for forming a thin film of a perovskite compound, characterized in that the step of supplying the C precursor is carried out before the step of supplying the B precursor and the step of primarily supplying the X precursor.

15. forming a crystalline solar cell; forming a buffer layer on the crystalline solar cell; forming a perovskite solar cell on the buffer layer; and forming a first electrode on the perovskite solar cell and a second electrode on the crystalline solar cell; A method for manufacturing a solar cell, wherein the step of forming the perovskite solar cell comprises the method for forming a thin film of a perovskite compound according to claim 1.

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