Perovskite solar cell and method for manufacturing the same

Abstract

The present invention provides a solar cell comprising a light absorption layer containing a perovskite compound and an electron transport layer provided on one surface of the light absorption layer, wherein the electron transport layer comprises a first electron transport layer provided on one surface of the light absorption layer and a second electron transport layer provided on the first electron transport layer, the first electron transport layer comprises an inorganic metal nitride, and the second electron transport layer comprises an inorganic metal oxynitride, and a method for manufacturing the same.

Description

TECHNICAL FIELD

[0001] The present invention relates to a perovskite solar cell and a manufacturing method thereof, and more specifically, relates to an electron transport layer.

BACKGROUND ART

[0002] A perovskite solar cell comprises a light absorption layer containing a perovskite compound, an electron transport layer provided on one surface of the light absorption layer, and a hole transport layer provided on the other surface of the light absorption layer.

[0003] Conventionally, a structure in which an organic material layer of C60 and a metal oxide layer are sequentially stacked has been used as the electron transport layer. However, in the case of such a structure, there is a problem that the metal oxide layer passes through the organic material layer of C60 and oxidizes the perovskite compound constituting the light absorption layer, thereby reducing the efficiency of the solar cell.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] The present invention has been devised to solve the above-mentioned conventional problems, and an object of the present invention is to provide a solar cell having an electron transport layer capable of preventing oxidation of a perovskite compound constituting a light absorption layer, and a manufacturing method thereof.

MEANS FOR SOLVING THE PROBLEMS

[0005] To achieve the above object, the present invention comprises a light absorption layer containing a perovskite compound, and an electron transport layer provided on one surface of the light absorption layer, wherein the electron transport layer comprises a first electron transport layer provided on one surface of the light absorption layer and a second electron transport layer provided on the first electron transport layer, the first electron transport layer comprises an inorganic metal nitride, and the second electron transport layer comprises an inorganic metal nitride oxide, or the first electron transport layer comprises an inorganic metal sulfide, and the second electron transport layer provides a solar cell comprising an inorganic metal sulfide oxide.

[0006] The present invention also provides a solar cell comprising a light-absorbing layer containing a perovskite compound, and an electron transport layer provided on one surface of the light-absorbing layer, wherein the first electron transport layer comprises a first electron transport layer provided on one surface of the light-absorbing layer and a third electron transport layer provided on the first electron transport layer, the first electron transport layer contains an inorganic metal nitride or inorganic metal sulfide, and the third electron transport layer contains an inorganic metal nitride oxide.

[0007] The present invention also provides a method for manufacturing a solar cell, comprising the steps of forming a light-absorbing layer containing a perovskite compound, and forming an electron transport layer on one surface of the light-absorbing layer, wherein the step of forming the electron transport layer comprises the steps of forming an electron transport precursor layer containing an inorganic metal nitride or inorganic metal sulfide, and performing oxygen plasma treatment on the electron transport precursor layer to form a first electron transport layer containing the inorganic metal nitride or inorganic metal sulfide and a second electron transport layer containing an inorganic metal nitride oxide or inorganic metal sulfide oxide.

[0008] The present invention also provides a method for manufacturing a solar cell, comprising the steps of forming a light-absorbing layer containing a perovskite compound, and forming an electron-absorbing layer on one surface of the light-absorbing layer, wherein the step of forming the electron-transport layer comprises the steps of forming an electron-transport precursor layer containing an inorganic metal nitride or inorganic metal sulfide, and subjecting the electron-transport precursor layer to oxygen plasma treatment to form a first electron-transport layer containing the inorganic metal nitride or inorganic metal sulfide and a third electron-transport layer containing an inorganic metal oxide. [Effects of the Invention]

[0009] According to the present invention as described above, the following effects are obtained.

[0010] According to one embodiment of the present invention, an electron transport precursor layer is formed on a light-absorbing layer, consisting of an inorganic nitride, particularly an oxygen-free inorganic nitride, specifically SnN or ZnN, or an electron transport precursor layer is formed on a light-absorbing layer, consisting of an inorganic sulfide, particularly an oxygen-free inorganic sulfide, specifically SnS, SnS2, or ZnS. As a result, since the inorganic nitride such as SnN or ZnN, or the inorganic sulfide such as SnS, SnS2, or ZnS, does not contain oxygen, oxidation of the perovskite compound constituting the light-absorbing layer can be prevented during the process of forming the electron transport precursor layer.

[0011] According to one embodiment of the present invention, the first electron transport layer containing the inorganic nitride or inorganic sulfide can function as a damage prevention film or barrier film for the underlying film. Furthermore, the second electron transport layer containing the inorganic metal nitride oxide or inorganic metal sulfide oxide can function as a damage prevention film or barrier film for the underlying film.

[0012] According to one embodiment of the present invention, a first electron transport layer is formed on the light-absorbing layer, consisting of an inorganic nitride, particularly an oxygen-free inorganic nitride, specifically SnN or ZnN, or a first electron transport layer is formed on the light-absorbing layer, consisting of an inorganic sulfide, particularly an oxygen-free inorganic sulfide, specifically SnS, SnS2, or ZnS. As a result, since the inorganic nitride such as SnN or ZnN, or the inorganic sulfide such as SnS, SnS2, or ZnS, does not contain oxygen, oxidation of the perovskite compound constituting the light-absorbing layer provided beneath the first electron transport layer can be prevented.

[0013] According to one embodiment of the present invention, the electrical conductivity characteristics can be improved by making the thickness of the second electron transport layer 52 thicker than the thickness of the first electron transport layer. [Brief explanation of the drawing]

[0014] [Figure 1A] This is a diagram illustrating the manufacturing process of a solar cell according to one embodiment of the present invention. [Figure 1B] This is a diagram illustrating the manufacturing process of a solar cell according to one embodiment of the present invention. [Figure 1C] This is a manufacturing process diagram of a solar cell according to one embodiment of the present invention. [Figure 1D] This is a manufacturing process diagram of a solar cell according to one embodiment of the present invention. [Figure 2A] This is a manufacturing process diagram of a solar cell according to another embodiment of the present invention. [Figure 2B] This is a manufacturing process diagram of a solar cell according to another embodiment of the present invention. [Figure 2C] This is a manufacturing process diagram of a solar cell according to another embodiment of the present invention. [Figure 2D] This is a manufacturing process diagram of a solar cell according to another embodiment of the present invention. [Figure 2E] This is a manufacturing process diagram of a solar cell according to another embodiment of the present invention. [Figure 3A] This is a manufacturing process diagram of a solar cell according to still another embodiment of the present invention. [Figure 3B] This is a manufacturing process diagram of a solar cell according to still another embodiment of the present invention. [Figure 3C] This is a manufacturing process diagram of a solar cell according to still another embodiment of the present invention. [Figure 3D] This is a manufacturing process diagram of a solar cell according to still another embodiment of the present invention. [Figure 3E] This is a manufacturing process diagram of a solar cell according to still another embodiment of the present invention. [Figure 3F] This is a manufacturing process diagram of a solar cell according to still another embodiment of the present invention. [Figure 3G] This is a manufacturing process diagram of a solar cell according to still another embodiment of the present invention. [Figure 4A] This is a manufacturing process diagram of a solar cell according to still another embodiment of the present invention. [Figure 4B] This is a manufacturing process diagram of a solar cell according to still another embodiment of the present invention. [Figure 4C] This is a manufacturing process diagram of a solar cell according to still another embodiment of the present invention. [Figure 4D] This is a manufacturing process diagram of a solar cell according to still another embodiment of the present invention. [Figure 4E]This is a diagram illustrating the manufacturing process of a solar cell according to yet another embodiment of the present invention. [Figure 4F] This is a diagram illustrating the manufacturing process of a solar cell according to yet another embodiment of the present invention. [Figure 4G] This is a diagram illustrating the manufacturing process of a solar cell according to yet another embodiment of the present invention. [Figure 4H] This is a diagram illustrating the manufacturing process of a solar cell according to yet another embodiment of the present invention. [Figure 5A] This is a diagram illustrating the manufacturing process of a solar cell according to yet another embodiment of the present invention. [Figure 5B] This is a diagram illustrating the manufacturing process of a solar cell according to yet another embodiment of the present invention. [Figure 5C] This is a diagram illustrating the manufacturing process of a solar cell according to yet another embodiment of the present invention. [Figure 5D] This is a diagram illustrating the manufacturing process of a solar cell according to yet another embodiment of the present invention. [Modes for carrying out the invention]

[0015] The advantages and features of the present invention, as well as methods for achieving them, will become apparent by referring to the embodiments described below in detail with accompanying figures. However, the present invention is not limited to the embodiments disclosed below, but can be embodied in a variety of different forms, and these embodiments are provided merely to complete the disclosure of the present invention and to fully inform those who are ordinary skill in the art to which the invention pertains, of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0016] The shapes, sizes, proportions, angles, numbers, etc., disclosed in the figures illustrating embodiments of the present invention are illustrative, and the present invention is not limited to those shown in the figures. Throughout the specification, the same reference numeral refers to the same component. In the description of the present invention, if a specific description of related prior art is deemed to unnecessarily obscure the gist of the invention, such detailed description will be omitted. Where the words "includes," "has," "consists of," etc., used in the present invention, other parts may be added unless "only" is used. When a component is expressed singularly, it includes multiple components unless otherwise explicitly stated.

[0017] In interpreting the constituent elements, even if there is no separate explicit mention of the error range, it shall be interpreted as including the error range.

[0018] When describing spatial relationships, for example, when the positional relationship between two parts is described using phrases such as "above," "above," "below," or "beside," one or more other parts may be located between the two parts, unless the expressions "immediately" or "directly" are used.

[0019] When describing temporal relationships, for example, when a temporal sequence is described using phrases like "after," "following," "next," or "before," it can include non-continuous events unless expressions like "immediately" or "directly" are used.

[0020] The terms "first," "second," etc., are used to describe various components, but these components are not limited by these terms. These terms are simply used to distinguish one component from another. Therefore, the first component referred to below may also be the second component within the technical concept of the present invention.

[0021] The features of each of the various embodiments of the present invention can be combined or linked together, either partially or as a whole, allowing for a variety of technically diverse interlocking and driving processes. Each embodiment can be implemented independently of the others or together in a related manner.

[0022] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the figures.

[0023] Figures 1A to 1D are manufacturing process diagrams for a solar cell according to one embodiment of the present invention.

[0024] First, as shown in Figure 1A, a first electrode 20 is formed on a substrate 10, a hole transport layer 30 is formed on the first electrode 20, and a light absorption layer 40 is formed on the hole transport layer 30.

[0025] The substrate 10 can be made of a material known in the industry, such as glass or plastic.

[0026] The first electrode 20 may be made of a conductive oxide such as ITO, but is not necessarily limited to this. The first electrode 20 can be formed by a deposition process such as ALD (Atomic Layer Deposition).

[0027] The hole transport layer 30 may comprise a variety of P-type organic compounds known in the industry, such as Spiro-MeO-TAD, Spiro-TTB, polyaniline, polypinol, poly-3,4-ethylenedioxythiophene-polystyrene sulfonate (PEDOT-PSS), or poly-[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly(3-hexylthiophene-2,5-diyl) (P3HT), a variety of P-type metal oxides known in the industry, such as Ni oxide, Mo oxide or V oxide, W oxide, Cu oxide, and other various P-type organic or inorganic compounds known in the industry. The hole transport layer 30 can be formed by a vapor deposition process such as CVD (Chemical Vapor Deposition) or ALD (Atomic Layer Deposition).

[0028] The light-absorbing layer 40 is made of a perovskite compound.

[0029] The perovskite compound can be obtained by reacting at least one compound selected from amine compounds and amidine compounds, an organometallic compound containing a divalent cation, and at least one hydrogen halide via a CVD (Chemical Vapor Deposition) or ALD (Atomic Layer Deposition) process to deposit and form the ABX3 compound.

[0030] In ABX3, A may consist of a monovalent organic cation of the amine compound, or a monovalent organic cation of the amidine compound, or it may contain both the monovalent organic cation of the amine compound and the 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 an x ​​ratio and the monovalent organic cation of the amidine compound is contained in a y ratio. Here, x and y are each greater than 0, and x + y = 1.

[0031] In ABX3, B is composed of the divalent cation.

[0032] In the aforementioned ABX3, X consists of at least one halogen compound.

[0033] The amine compound can be selected from the group consisting of methylamine, ethylamine, and phenethylamine.

[0034] The aforementioned amidine-based compound may consist of formamidine.

[0035] The organometallic compound containing the divalent cation may include a metal selected from the group consisting of Pb, Sn, Ge, Sb, Bi, and Ba.

[0036] Specifically, the organometallic compound containing the divalent cation is defined by the following chemical formula 1:

[0037] [ka]

[0038] (In the formula, R 1 ~R 12 Each of the elements independently consists of either hydrogen or an alkyl group, and X can be a compound represented by (selected from the group consisting of Pb, Sn, Ge, Sb, Bi, and Ba).

[0039] Alternatively, the organometallic compounds containing the divalent cation are 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 You can choose from the group consisting of N2O2Pb.

[0040] The type of organometallic compound containing the divalent cation can be used to control the light absorption rate, band gap, carrier mobility, and material stability of the final perovskite compound.

[0041] The hydrogen halide can be selected from the group consisting of HI, HBr, Hf, and HCl. The type of hydrogen halide can be used to adjust the band gap of the final perovskite compound.

[0042] The amine compound, the amidine compound, the organometallic compound containing a divalent cation, and the hydrogen halide are substances that vaporize at temperatures ranging from room temperature to 200°C, preferably at temperatures ranging from 50°C to 150°C. This allows the process of producing the ABX3 compound to be carried out at temperatures of 200°C or lower, preferably 150°C or lower, through a chemical vapor deposition (CVD) process or atomic layer deposition (ALD) process, thereby preventing the organic matter in the final ABX3 compound from decomposing during the CVD or ALD process. Alternatively, plasma can be applied when performing the CVD or ALD process.

[0043] According to another embodiment of the present invention, the perovskite compound can be obtained by reacting at least one compound selected from amine compounds and amidine compounds, at least one alkali metal compound, an organometallic compound containing a divalent cation, and a hydrogen halide via a CVD (Chemical Vapor Deposition) or ALD (Atomic Layer Deposition) process to deposit and form the CABX3 compound.

[0044] In CABX3, A may consist of a monovalent organic cation of the amine compound, or a monovalent organic cation of the amidine compound, or may consist of a monovalent organic cation of the amine compound and a monovalent organic cation of the amidine series compound.

[0045] In the CABX3, C can consist of at least one of the alkali metals.

[0046] The CA can have a structure in which a monovalent organic cation of the amine compound is contained in a ratio of x, a monovalent organic cation of the amidine compound is contained in a ratio of y, and a monovalent cation of the alkali metal is contained in a ratio of z. Here, x, y, and z are each greater than 0, and x + y + z = 1.

[0047] In the CABX3 described above, B consists of the divalent cation, and X consists of at least one halogen compound.

[0048] The amine series compounds, the amidine series compounds, the organometallic compounds containing divalent cations, and the hydrogen halides are the same as those described above, so a repeated explanation will be omitted.

[0049] The alkali metal compound is given by the following chemical formula 2:

[0050] [ka]

[0051] (In the formula, R 1 ~R 6 The compounds can consist of a compound represented by (where each is independently composed of hydrogen or an alkyl group, and Y is an alkali metal).

[0052] As described below, according to other embodiments 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 compound to the reactants.

[0053] Next, as can be seen from Figure 1B, an electron transport precursor layer 50a is formed on the light absorption layer 40.

[0054] The electron transport precursor layer 50a can be made of an inorganic nitride, particularly an oxygen-free inorganic nitride. Specifically, the electron transport precursor layer 50a can be made of SnN or ZnN.

[0055] The electron transport precursor layer 50a can consist of an inorganic sulfide, particularly an oxygen-free inorganic sulfide. Specifically, the electron transport precursor layer 50a can consist of SnS, SnS2, or ZnS.

[0056] The inorganic nitride such as SnN or ZnN can be formed by a vapor deposition process such as CVD or ALD. Since the inorganic nitride such as SnN or ZnN does not contain oxygen, oxidation of the perovskite compound constituting the light absorption layer 40 can be prevented during the process of forming the electron transport precursor layer 50a.

[0057] The inorganic sulfides such as SnS, SnS2, or ZnS can be formed by a vapor deposition process such as CVD or ALD. Since the inorganic sulfides such as SnS, SnS2, or ZnS do not contain oxygen, oxidation of the perovskite compound constituting the light absorption layer 40 can be prevented during the process of forming the electron transport precursor layer 50a.

[0058] Next, as can be seen in Figure 1C, the electron transport precursor layer 50a is subjected to oxygen plasma treatment.

[0059] As a result, oxygen is introduced into the inorganic metal nitride such as SnN or ZnN, and the electron transport precursor layer 50a can be transformed into an electron transport layer 50 including a first electron transport layer 51, a second electron transport layer 52, and a third electron transport layer 53.

[0060] Alternatively, oxygen can be introduced into the inorganic metal sulfide such as SnS, SnS2, and ZnS, and the electron transport precursor layer 50a can be transformed into an electron transport layer 50 including a first electron transport layer 51, a second electron transport layer 52, and a third electron transport layer 53.

[0061] The first electron transport layer 51 is a layer in contact with the light absorption layer 40 and is made of the same material as the inorganic metal nitride or inorganic metal sulfide that constitutes the electron transport precursor layer 50a without the introduction of oxygen. Therefore, the first electron transport layer 51 can be made of an oxygen-free inorganic metal nitride, specifically SnN or ZnN, or an oxygen-free inorganic metal sulfide, specifically SnS, SnS2, or ZnS.

[0062] Since the inorganic nitrides such as SnN and ZnN, and the inorganic sulfides such as SnS, SnS2, or ZnS do not contain oxygen, they can prevent oxidation of the perovskite compound constituting the light absorption layer provided beneath the first electron transport layer 51. Therefore, the first electron transport layer 51 containing the inorganic nitride or inorganic sulfide can function as a damage prevention film or barrier film for the underlying film.

[0063] The second electron transport layer 52 is a layer formed on the first electron transport layer 51 in contact with the first electron transport layer 51, and is a layer in which oxygen is partially introduced into the inorganic metal nitride or inorganic metal sulfide constituting the electron transport precursor layer 50a. Therefore, the second electron transport layer 52 can consist of an inorganic metal nitride oxide, specifically SnON or ZnON, or an inorganic metal sulfide oxide, specifically SnOS or ZnOS. The second electron transport layer 52 containing the inorganic metal nitride oxide or inorganic metal sulfide oxide can function as a damage prevention film or barrier film for the underlying film.

[0064] The third electron transport layer 53 is a layer formed on the second electron transport layer 52 in contact with the second electron transport layer 52, and is a layer in which oxygen is introduced into the inorganic metal nitride constituting the electron transport precursor layer 50a, thereby replacing nitrogen with oxygen, or oxygen is introduced into the inorganic metal sulfide constituting the electron transport precursor layer 50a, thereby replacing sulfur with oxygen. Therefore, the third electron transport layer 53 can be made of an inorganic metal oxide, specifically SnO or ZnO.

[0065] The first electron transport layer 51 is made of an oxygen-free inorganic metal nitride or inorganic metal sulfide, specifically SnN, ZnN, SnS, SnS2, or ZnS. Therefore, it has the advantage of preventing oxidation of the perovskite compound constituting the light absorption layer 40 provided beneath it, but it has the disadvantage of poor electrical conductivity.

[0066] In contrast, the second electron transport layer 52 is made of an inorganic metal nitride oxide or an inorganic metal sulfide oxide, specifically SnON, ZnON, SnOS, or ZnOS, and therefore has superior electrical conductivity characteristics compared to the first electron transport layer 51. Accordingly, in order to improve the electrical conductivity characteristics, it is preferable to form the second electron transport layer 52 with a thickness (t2) greater than the thickness (t1) of the first electron transport layer 51.

[0067] In some cases, the second electron transport layer 52 may not be formed in the process shown in Figure 1C. Specifically, by performing oxygen plasma treatment on the electron transport precursor layer 50a, the third electron transport layer 53 can be directly formed on the upper surface of the first electron transport layer 51 instead of forming the second electron transport layer 52 on the same upper surface of the first electron transport layer 51 as the electron transport precursor layer 50a.

[0068] As an example, a third electron transport layer 53 made of SnO or ZnO can be directly formed on the upper surface of the first electron transport layer 51 containing an inorganic metal nitride such as SnN or ZnN, or a third electron transport layer 53 made of SnO or ZnO can be directly formed on the upper surface of the first electron transport layer 51 containing an inorganic metal sulfide such as SnS, SnS2, or ZnS. In this case, the thickness of the third electron transport layer 53 will be greater than the thickness of the first electron transport layer 51.

[0069] Next, as can be seen from Figure 1D, a transparent conductive layer 60 is formed on the electron transport layer 50, and a second electrode 70 is formed on the transparent conductive layer 60.

[0070] The transparent conductive layer 60 may contain a substance having electron transport properties. The transparent conductive layer 60 may contain ITO or IZO, but is not necessarily limited to these. The transparent conductive layer 60 can be formed by a vapor deposition process such as ALD.

[0071] The second electrode 70 can be made of a metallic substance such as Ag. The second electrode 70 can be patterned in a predetermined shape so that sunlight can enter the inside of the battery.

[0072] Figures 2A to 2E are manufacturing process diagrams for a solar cell according to another embodiment of the present invention.

[0073] First, as can be seen from Figure 2A, the first electrode 20 is formed on the substrate 10, a hole transport layer 30 is formed on the first electrode 20, and a light absorption layer 40 is formed on the hole transport layer 30.

[0074] The specific configurations of the substrate 10, the first electrode 20, the hole transport layer 30, and the light absorption layer 40 are the same as in the embodiment described above, so a repeated explanation will be omitted.

[0075] Next, as can be seen from Figure 2B, an electron transport precursor layer 50a is formed on the light absorption layer 40.

[0076] Since the specific configuration of the electron transport precursor layer 50a is the same as in the embodiment described above, a repeated explanation will be omitted.

[0077] Next, as can be seen in Figure 2C, the electron transport precursor layer 50a is subjected to oxygen plasma treatment.

[0078] This allows oxygen to be introduced into the inorganic metal nitride such as SnN or ZnN, transforming the electron transport precursor layer 50a into a first electron transport layer 51 and a second electron transport layer 52.

[0079] Alternatively, the electron transport precursor layer 50a can be transformed into a first electron transport layer 51 and a second electron transport layer 52 by introducing oxygen into an inorganic metal sulfide such as SnS, SnS2, or ZnS.

[0080] The first electron transport layer 51 is a layer in contact with the light absorption layer 40 and is made of the same material as the inorganic metal nitride or inorganic metal sulfide that constitutes the electron transport precursor layer 50a without the introduction of oxygen. Therefore, the first electron transport layer 51 can be made of an oxygen-free inorganic metal nitride, specifically SnN or ZnN, or an oxygen-free inorganic metal sulfide, specifically SnS, SnS2, or ZnS.

[0081] The second electron transport layer 52 is a layer formed on the first electron transport layer 51, and is a layer in which oxygen is partially introduced into the inorganic metal nitride or inorganic metal sulfide that constitutes the electron transport precursor layer 50a. Therefore, the second electron transport layer 52 can consist of an inorganic metal nitride oxide, specifically SnON or ZnON, or an inorganic metal sulfide oxide, specifically SnOS or ZnOS.

[0082] Similar to the embodiments described above, it is preferable that the thickness (t2) of the second electron transport layer 52 is greater than the thickness (t1) of the first electron transport layer 51.

[0083] In the process shown in Figure 1C described above, the third electron transport layer 53 was further formed on the second electron transport layer 52 by oxygen plasma treatment of the electron transport precursor layer 50a. However, depending on the process conditions, even if oxygen is introduced into the inorganic metal nitride or inorganic metal sulfide constituting the electron transport precursor layer 50a, the nitrogen or sulfur may not be completely replaced by oxygen, and therefore the third electron transport layer 53 may not be formed.

[0084] Next, as can be seen from Figure 2D, a third electron transport layer 53 is formed on the second electron transport layer 52, thereby forming an electron transport layer 50 including the first electron transport layer 51, the second electron transport layer 52, and the third electron transport layer 53.

[0085] The third electron transport layer 53 can be made of an inorganic metal oxide, specifically SnO or ZnO. The third electron transport layer 53 can be formed by a deposition process such as ALD.

[0086] Here, it is preferable for the thickness (t3) of the third electron transport layer 53 to be greater than the thickness (t1) of the first electron transport layer 51 in order to improve electrical conductivity characteristics. Furthermore, the thickness (t3) of the third electron transport layer 53 can be greater than the thickness (t2) of the second electron transport layer 52.

[0087] In some cases, the step shown in Figure 2C described above can be omitted, and the step shown in Figure 2D can be performed after the step shown in Figure 2B described above, thereby forming the third electron transport layer 53, which is made of an inorganic metal oxide, specifically SnO or ZnO, on the upper surface of the first electron transport layer 51, which is made of the electron transport precursor layer 50a.

[0088] Next, as can be seen from Figure 2E, a transparent conductive layer 60 is formed on the electron transport layer 50, and a second electrode 70 is formed on the transparent conductive layer 60.

[0089] Since the specific configurations of the transparent conductive layer 60 and the second electrode 70 are the same as those described in the previous embodiment, a repeated explanation will be omitted.

[0090] In the above embodiments, a hole transport layer 30 is formed on the lower surface of the light absorption layer 40 and an electron transport layer 50 is formed on the upper surface of the light absorption layer 40. However, the embodiments are not necessarily limited to this configuration. The hole transport layer 30 can also be formed on the upper surface of the light absorption layer 40 and the electron transport layer 50 on the lower surface of the light absorption layer 40, and the same applies to the following embodiments.

[0091] Figures 3A to 3G are manufacturing process diagrams for solar cells according to the present invention and other embodiments, relating to tandem solar cells of perovskite solar cells and crystalline solar cells.

[0092] First, as can be seen from Figure 3A, a crystalline solar cell 100 is manufactured.

[0093] The crystalline solar cell 100 can be manufactured by etching one surface and the other surface of a semiconductor substrate 110 such as a wafer to form an uneven structure, doping one surface of the semiconductor substrate 110 with a predetermined dopant to form a first semiconductor layer 120, and doping the other surface of the semiconductor substrate 110 with a predetermined dopant to form a second semiconductor layer 130.

[0094] Since one side and the other side of the semiconductor substrate 110 are formed with an uneven structure, the first semiconductor layer 120 and the second semiconductor layer 130 each have shapes corresponding to the uneven structure.

[0095] On the other hand, the figure shows a configuration in which both sides of the semiconductor substrate 110 are formed with an uneven structure. However, the invention is not limited to this configuration. One of the two sides of the semiconductor substrate 110 may be formed with an uneven structure, while the other side may be formed with a flat structure. In some cases, both sides of the semiconductor substrate 110 may be formed with a flat structure.

[0096] The semiconductor substrate 110 can be made of a P-type or N-type wafer, the first semiconductor layer 120 can be doped with a dopant having a different polarity from the semiconductor substrate 110, and the second semiconductor layer 130 can be doped with a dopant having the same polarity as the semiconductor substrate 110. For example, the semiconductor substrate 110 can be made of a P-type wafer, the first semiconductor layer 120 can be doped with an N-type dopant, and the second semiconductor layer 130 can be doped with a P-type dopant to form a P+ layer.

[0097] Next, as can be seen from Figure 3B, a buffer layer 200 is formed on the upper surface of the crystalline solar cell 100.

[0098] The buffer layer 200 is formed on the first semiconductor layer 120. Because the first semiconductor layer 120 is formed with an uneven structure, the buffer layer 200 also has an uneven structure.

[0099] The buffer layer 200 is provided between the crystalline solar cell 100 and the perovskite solar cell 300, which will be described later, so that the solar cell according to one embodiment of the present invention has the structure of a tandem solar cell through a tunnel junction.

[0100] The buffer layer 200 is preferably made of a material that allows long-wavelength light transmitted through the perovskite solar cell to be incident on the crystalline solar cell 100 without loss. For example, the buffer layer 200 can be made of a transparent conductive oxide, a carbonaceous conductive material, a metallic material, or a conductive polymer, and in some cases, the material can be doped with an n-type or p-type dopant.

[0101] Next, as can be seen in Figure 3C, a hole transport layer 30 is formed on the buffer layer 200, and a light absorption layer 40 is formed on the hole transport layer 30.

[0102] The specific configurations of the hole transport layer 30 and the light absorption layer 40 are the same as in the embodiment described above, so a repeated explanation will be omitted.

[0103] Next, as can be seen from Figure 3D, an electron transport precursor layer 50a is formed on the light absorption layer 40.

[0104] The specific configuration of the electron transport precursor layer 50a is the same as in the embodiment described above, so a repeated explanation will be omitted.

[0105] Next, as can be seen in Figure 3E, the electron transport precursor layer 50a is subjected to oxygen plasma treatment.

[0106] As a result, oxygen is introduced into an inorganic metal nitride such as SnN or ZnN, or an inorganic metal sulfide such as SnS2 or ZnS, and the electron transport precursor layer 50a can be transformed into an electron transport layer 50 including a first electron transport layer 51, a second electron transport layer 52, and a third electron transport layer 53.

[0107] The specific configuration of the electron transport layer 50, including the first electron transport layer 51, the second electron transport layer 52, and the third electron transport layer 53, is the same as that shown in Figure 1C above, so a repeated explanation will be omitted.

[0108] Next, as can be seen from Figure 3F, a transparent conductive layer 60 is formed on the electron transport layer 50.

[0109] The specific configuration of the transparent conductive layer 60 is the same as in the embodiment described above, so a repeated explanation will be omitted.

[0110] Next, as can be seen from Figure 3G, a first electrode 20 is formed on the lower surface of the crystalline solar cell 100, and a second electrode 70 is formed on the upper surface of the transparent conductive layer 60.

[0111] Since the second electrode 70 is formed on the incident surface to which sunlight enters, it is patterned in a predetermined shape. The first electrode 20 is also patterned in a predetermined shape, so that reflected sunlight enters the inside of the solar cell, but it is not necessarily limited to this.

[0112] The first electrode 20 and the second electrode 70 can be formed from a variety of conductive materials known in the industry by a variety of pattern formation methods.

[0113] Although not specifically shown in the figure, a passivation layer can be formed on the second electrode 70. Here, a portion of the passivation layer is etched to expose the second electrode 70.

[0114] Figures 4A to 4H are manufacturing process diagrams for solar cells according to the present invention and other embodiments, relating to tandem solar cells of perovskite and crystalline materials.

[0115] First, as can be seen from Figure 4A, a crystalline solar cell 100 is manufactured.

[0116] The crystalline solar cell 100 can be manufactured by etching one surface and the other surface of the semiconductor substrate 110, such as a wafer, to form an uneven structure; doping one surface of the semiconductor substrate 110 with a predetermined dopant to form a first semiconductor layer 120; and doping the other surface of the semiconductor substrate 110 with a predetermined dopant to form a second semiconductor layer 130.

[0117] The specific configurations of the semiconductor substrate 110, the first semiconductor layer 120, and the second semiconductor layer 130 are the same as those shown in Figure 3A above, so a repeated explanation will be omitted.

[0118] Next, as can be seen from Figure 4B, a buffer layer 200 is formed on the upper surface of the crystalline solar cell 100.

[0119] The specific configuration of the buffer layer 200 is the same as that shown in Figure 3B above, so a repeated explanation will be omitted.

[0120] Next, as can be seen in Figure 4C, a hole transport layer 30 is formed on the buffer layer 200, and a light absorption layer 40 is formed on the hole transport layer 30.

[0121] The specific configurations of the hole transport layer 30 and the light absorption layer 40 are the same as those shown in Figure 3C above, so a repeated explanation will be omitted.

[0122] Next, as can be seen from Figure 4D, an electron transport precursor layer 50a is formed on the light absorption layer 40.

[0123] The specific configuration of the electron transport precursor layer 50a is the same as that shown in Figure 3D above, so a repeated explanation will be omitted.

[0124] Next, as can be seen in Figure 4E, the electron transport precursor layer 50a is subjected to oxygen plasma treatment.

[0125] As a result, oxygen is introduced into the inorganic metal nitride such as SnN or ZnN, or the inorganic metal sulfide such as SnS2 or ZnS, and the electron transport precursor layer 50a is transformed into the first electron transport layer 51 and the second electron transport layer 52.

[0126] The specific configurations of the first electron transport layer 51 and the second electron transport layer 52 are the same as those shown in Figure 2C above, so a repeated explanation will be omitted.

[0127] Next, as can be seen from Figure 4F, a third electron transport layer 53 is formed on the second electron transport layer 52, thereby forming an electron transport layer 50 including the first electron transport layer 51, the second electron transport layer 52, and the third electron transport layer 53.

[0128] The specific configuration of the third electron transport layer 53 is the same as that shown in Figure 2D above, so a repeated explanation will be omitted. Similar to the embodiment described above, the electron transport layer 50, including the first electron transport layer 51 and the third electron transport layer 53 provided on the upper surface of the first electron transport layer 51, can also be formed by omitting the step shown in Figure 4E and performing the step shown in Figure 4F after the step shown in Figure 4D.

[0129] Next, as can be seen from Figure 4G, a transparent conductive layer 60 is formed on the electron transport layer 50.

[0130] The specific configuration of the transparent conductive layer 60 is the same as that shown in Figure 3F above, so a repeated explanation will be omitted.

[0131] Next, as can be seen from Figure 4H, a first electrode 20 is formed on the lower surface of the crystalline solar cell 100, and a second electrode 70 is formed on the upper surface of the transparent conductive layer 60.

[0132] The specific configurations of the first electrode 20 and the second electrode 70 are the same as those shown in Figure 3G above, so a repeated explanation will be omitted.

[0133] Although not specifically shown in the figure, a passivation layer can be formed on the second electrode 70. Here, a portion of the passivation layer is etched to expose the second electrode 70.

[0134] Figures 5A to 5D are manufacturing process diagrams for a solar cell according to yet another embodiment of the present invention, which differ from Figures 1A to 1D described above in that they further include the process of forming the passivation layer 80 and the organic material layer 90.

[0135] First, as can be seen from Figure 5A, a first electrode 20 is formed on the substrate 10, a hole transport layer 30 is formed on the first electrode 20, a light absorption layer 40 is formed on the hole transport layer 30, a passivation layer 80 is formed on the light absorption layer 40, and an organic material layer 90 is formed on the passivation layer 80.

[0136] The specific configurations of the substrate 10, the first electrode 20, the hole transport layer 30, and the light absorption layer 40 are the same as in the embodiment described above, so a repeated explanation will be omitted.

[0137] The passivation layer 80 may consist of an inorganic insulating layer, such as an oxygen-free inorganic insulating layer like silicon nitride.

[0138] The organic layer 90 may consist of fullerene or a fullerene derivative. For example, the organic layer 90 may consist of C60 or PCBM ([6,6]-phenyl-C61-butanoate methyl ester).

[0139] Next, as can be seen from Figure 5B, an electron transport precursor layer 50a is formed on the light absorption layer 40.

[0140] The specific configuration of the electron transport precursor layer 50a is the same as that shown in Figure 1B above, so a repeated explanation will be omitted.

[0141] Next, as can be seen in Figure 5C, the electron transport precursor layer 50a is subjected to oxygen plasma treatment.

[0142] As a result, oxygen is introduced into the inorganic metal nitride such as SnN or ZnN, and the electron transport precursor layer 50a can be transformed into an electron transport layer 50 including a first electron transport layer 51, a second electron transport layer 52, and a third electron transport layer 53.

[0143] Alternatively, oxygen can be introduced into an inorganic metal sulfide such as SnS, SnS2, or ZnS, thereby transforming the electron transport precursor layer 50a into an electron transport layer 50 containing a first electron transport layer 51, a second electron transport layer 52, and a third electron transport layer 53.

[0144] The specific configurations of the first electron transport layer 51, the second electron transport layer 52, and the third electron transport layer 53 are the same as those shown in Figure 1C above, so a repeated explanation will be omitted.

[0145] Here, the first electron transport layer 51 and the second electron transport layer 52 can function as damage prevention films or barrier films that prevent damage to the passivation layer 80 and the organic material layer 90.

[0146] Next, as can be seen from Figure 5D, a transparent conductive layer 60 is formed on the electron transport layer 50, and a second electrode 70 is formed on the transparent conductive layer 60.

[0147] The specific configurations of the transparent conductive layer 60 and the second electrode 70 are the same as those shown in Figure 1D above, so a repeated explanation will be omitted.

[0148] Although not specifically shown in the figures, the embodiments described in Figures 2A to 2E above can also include additional steps for forming the passivation layer 80 and the organic layer 90. That is, in the step shown in Figure 2A above, the passivation layer 80 and the organic layer 90 can be formed sequentially on the light absorption layer 40, and then in the step shown in Figure 2B, the electron transport precursor layer 50a can be formed on the organic layer 90.

[0149] Furthermore, the embodiments shown in Figures 3A to 3G described above can also include the additional steps of forming the passivation layer 80 and the organic layer 90. That is, in the step shown in Figure 3C described above, the passivation layer 80 and the organic layer 90 can be formed sequentially on the light absorption layer 40, and then in the step shown in Figure 3D, the electron transport precursor layer 50a can be formed on the organic layer 90.

[0150] Furthermore, the embodiments shown in Figures 4A to 4H described above can also include the additional steps of forming the passivation layer 80 and the organic layer 90. That is, the passivation layer 80 and the organic layer 90 can be formed sequentially on the light absorption layer 40 in the step shown in Figure 4C described above, and then the electron transport precursor layer 50a can be formed on the organic layer 90 in the step shown in Figure 4D.

[0151] Although embodiments of the present invention have been described in more detail above with reference to the attached figures, the present invention is not necessarily limited to these embodiments and can be implemented in various ways without departing from the technical concept of the present invention. Therefore, the embodiments disclosed herein are for illustrative purposes only and not to limit the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by such embodiments. Accordingly, the embodiments described above should be understood to be illustrative and not limiting in all respects. The scope of protection of the present invention should be interpreted by the claims, and all technical concepts within an equivalent scope should be interpreted as being included in the scope of rights of the present invention.

Claims

1. A light-absorbing layer containing a perovskite compound, and The light-absorbing layer comprises an electron transport layer provided on one surface of the light-absorbing layer, The electron transport layer comprises a first electron transport layer provided on one surface of the light absorption layer and a second electron transport layer provided on the first electron transport layer. A solar cell comprising an inorganic metal nitride in the first electron transport layer and an inorganic metal nitride oxide in the second electron transport layer.

2. The first electron transport layer comprises SnN, and the second electron transport layer comprises SnON, The solar cell according to claim 1, wherein the first electron transport layer comprises ZnN and the second electron transport layer comprises ZnON.

3. The solar cell according to claim 1, further comprising a passivation layer between the light-absorbing layer and the electron transport layer.

4. The solar cell according to claim 3, further comprising an organic layer between the passivation layer and the electron transport layer.

5. The solar cell according to claim 1, wherein the thickness of the second electron transport layer is greater than the thickness of the first electron transport layer.

6. The electron transport layer further comprises a third electron transport layer provided on the second electron transport layer, The solar cell according to claim 1, wherein the third electron transport layer comprises an inorganic metal oxide.

7. The solar cell according to claim 6, wherein the third electron transport layer comprises SnO or ZnO.

8. A buffer layer provided on the other surface of the light-absorbing layer, and The solar cell according to claim 1, further comprising a crystalline solar cell provided on the buffer layer.

9. A step of forming a light-absorbing layer containing a perovskite compound, and The process includes forming an electron transport layer on one surface of the light absorption layer, The step of forming the electron transport layer includes the step of forming an electron transport precursor layer containing an inorganic metal nitride, and A method for manufacturing a solar cell, comprising the step of performing oxygen plasma treatment on the electron transport precursor layer to form a first electron transport layer containing the inorganic metal nitride and a second electron transport layer containing an inorganic metal nitride oxide.

10. The electron transport precursor layer and the first electron transport layer contain SnN, and the second electron transport layer contains SnON, A method for manufacturing a solar cell according to claim 9, wherein the electron transport precursor layer and the first electron transport layer contain ZnN, and the second electron transport layer contains ZnON.

11. The process further includes forming a third electron transport layer containing an inorganic metal oxide on the second electron transport layer, The method for manufacturing a solar cell according to claim 9, wherein the third electron transport layer comprises SnO or ZnO.

12. A method for manufacturing a solar cell according to claim 9, further comprising the steps of forming a passivation layer between the light absorption layer and the electron transport layer, and forming an organic layer between the passivation layer and the electron transport layer.

13. The process further includes a step of forming a crystalline solar cell before the step of forming the light-absorbing layer, and a step of forming a buffer layer on the crystalline solar cell. The method for manufacturing a solar cell according to claim 9, wherein the light-absorbing layer is formed on the buffer layer.

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