Perovskite solar cell and manufacturing method thereof

Abstract

The present invention provides a solar cell and a method of manufacturing the same, the solar cell including a light absorbing layer including a perovskite compound, and an electron transport layer on one surface of the light absorbing layer, the electron transport layer is composed of a first electron transport layer on the one surface of the light absorption layer and a second electron transport layer on the first electron transport layer, the first electron transport layer being composed of an inorganic metal nitride and the second electron transport layer being composed of an inorganic metal nitrogen oxide.

Description

Technical Field

[0001] The invention relates to a perovskite solar cell and a manufacturing method thereof, in particular to an electron transport layer of a perovskite solar cell. Background Art

[0002] The perovskite solar cell includes a light absorbing layer including a perovskite compound, an electron transport layer located on one side of the light absorbing layer, and a hole transport layer located on the other side of the light absorbing layer.

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

[0004] Technical issues

[0005] The present invention aims to solve the above-mentioned problems and to provide a solar cell having an electron transport layer capable of preventing oxidation of a perovskite compound constituting a light absorbing layer and a method for manufacturing the same.

[0006] Technical Solution

[0007] In order to achieve the above-mentioned purpose, an embodiment of the present invention provides a solar cell, which includes a light absorption layer including a perovskite compound and an electron transport layer arranged on a first surface of the light absorption layer, wherein the electron transport layer includes a first electron transport layer arranged on the first surface of the light absorption layer and a second electron transport layer arranged on the first electron transport layer, and wherein the first electron transport layer includes an inorganic metal nitride and the second electron transport layer includes an inorganic metal nitride oxide, or the first electron transport layer includes an inorganic metal sulfide and the second electron transport layer includes an inorganic metal sulfide oxide.

[0008] Another embodiment of the present invention provides a solar cell, which includes a light absorbing layer including a perovskite compound and an electron transport layer arranged on a first surface of the light absorbing layer, wherein the electron transport layer includes a first electron transport layer arranged on the first surface of the light absorbing layer and a third electron transport layer arranged on the first electron transport layer, and wherein the first electron transport layer includes an inorganic metal nitride or an inorganic metal sulfide, and the third electron transport layer includes an inorganic metal oxide.

[0009] Another embodiment of the present invention provides a method for manufacturing a solar cell, the method comprising: forming a light absorbing layer comprising a perovskite compound; and forming an electron transport layer on a first surface of the light absorbing layer, wherein forming the electron transport layer comprises: forming an electron transport precursor layer comprising an inorganic metal nitride or an inorganic metal sulfide; and performing oxygen plasma treatment on the electron transport precursor layer to form a first electron transport layer comprising an inorganic metal nitride or an inorganic metal sulfide and a second electron transport layer comprising an inorganic metal oxynitride or an inorganic metal oxysulfide.

[0010] Another embodiment of the present invention provides a method for manufacturing a solar cell, the method comprising: forming a light absorbing layer comprising a perovskite compound; and forming an electron transport layer on a first surface of the light absorbing layer, wherein forming the electron transport layer comprises: forming an electron transport precursor layer comprising an inorganic metal nitride or an inorganic metal sulfide; and performing oxygen plasma treatment on the electron transport precursor layer to form a first electron transport layer comprising an inorganic metal nitride or an inorganic metal sulfide and a third electron transport layer comprising an inorganic metal oxide.

[0011] Beneficial Effects

[0012] According to the present invention, the following effects can be achieved.

[0013] According to an embodiment of the present invention, an electron transport precursor layer composed of an inorganic nitride (especially an inorganic nitride that does not contain oxygen, specifically SnN or ZnN) is formed on the light absorbing layer, or an electron transport precursor layer composed of an inorganic sulfide (especially an inorganic sulfide that does not contain oxygen, specifically SnS, SnS2 or ZnS) is formed on the light absorbing layer. Therefore, since an inorganic nitride such as SnN or ZnN or an inorganic sulfide such as SnS, SnS2 or ZnS does not contain oxygen, during the process of forming the electron transport precursor layer, oxidation of the perovskite compound constituting the light absorbing layer can be prevented.

[0014] According to an embodiment of the present invention, the first electron transport layer containing an inorganic nitride or an inorganic sulfide can act as a damage prevention film or barrier film for its underlying layer. In addition, the second electron transport layer containing an inorganic metal oxynitride or an inorganic metal oxysulfide can act as a damage prevention film or barrier film for its underlying layer.

[0015] According to an embodiment of the present invention, a first electron transport layer composed of an inorganic nitride (especially an inorganic nitride that does not contain oxygen, specifically SnN or ZnN) is formed on the light absorbing layer, or a first electron transport layer composed of an inorganic sulfide (especially an inorganic sulfide that does not contain oxygen, specifically SnS, SnS2 or ZnS) is formed on the light absorbing layer. Therefore, since an inorganic nitride such as SnN or ZnN or an inorganic sulfide such as SnS, SnS2 or ZnS does not contain oxygen, oxidation of the perovskite compound constituting the light absorbing layer disposed below the first electron transport layer can be prevented.

[0016] According to an embodiment of the present invention, the thickness of the second electron transport layer is thicker than that of the first electron transport layer, thereby improving conductive characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1a to Figure 1d is a process diagram for manufacturing a solar cell according to an embodiment of the present invention.

[0018] Figure 2a to Figure 2e is a process diagram for manufacturing a solar cell according to another embodiment of the present invention.

[0019] Figure 3a to Figure 3g is a process diagram for manufacturing a solar cell according to another embodiment of the present invention.

[0020] Figure 4a to Figure 4h is a process diagram for manufacturing a solar cell according to another embodiment of the present invention.

[0021] Figure 5a to Figure 5d is a process diagram for manufacturing a solar cell according to another embodiment of the present invention. DETAILED DESCRIPTION

[0022] The advantages and features of the present invention and the implementation method of the present invention will be explained by the embodiments described below with reference to the accompanying drawings. However, the present invention can be embodied in different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention will be thorough and complete, and will fully convey the scope of the present invention to those of ordinary skill in the art. In addition, the present invention is limited only by the scope of the claims.

[0023] The shapes, sizes, proportions, angles and quantities disclosed in the accompanying drawings for describing the embodiments of the present invention are only examples, and therefore the present invention is not limited to the details shown. Throughout the application, similar reference numerals represent similar elements. In the following description, when it is determined that the detailed description of the relevant known technology will unnecessarily obscure the focus of the present invention, such detailed description will be omitted. When using "including", "having" and "comprising" described in this specification, unless "only" is used, another component can be added. Unless otherwise specified, terms in the singular may include plural forms.

[0024] When explaining an element, although the error range is not described in detail, the element should be understood as including the error range.

[0025] When describing a positional relationship, for example, when the positional relationship between two components is described as "on", "above", "under", and "beside", unless "immediately" or "directly" is used, one or more other components may be arranged between the two components.

[0026] When describing a time relationship, for example, when describing a time sequence with "after," "subsequently," "next," and "before," discontinuous cases may be included unless "just" or "directly" is used.

[0027] It will be understood that although the terms "first", "second", etc. can be used to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the present invention, the first element can be named as the second element, and similarly, the second element can be named as the first element.

[0028] The term "at least one" should be understood to include any and all combinations of more than one of the related listed items. For example, "at least one of the first, second, and third items" means a combination of more than two of the first, second, and third items and all items proposed by the first, second, or third items.

[0029] The features of the various embodiments of the present invention may be combined or combined with each other in part or in whole, and may interact with each other in various ways and be technically driven in a manner that is fully understandable to those of ordinary skill in the art. The embodiments of the present invention may be implemented independently of each other, or may be implemented in a mutually dependent relationship.

[0030] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0031] Figure 1a to Figure 1dis a process diagram for manufacturing a solar cell according to an embodiment of the present invention.

[0032] First, if Figure 1a As shown, 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 .

[0033] The substrate 10 may be made of a material known in the art, such as glass or plastic.

[0034] The first electrode 20 may be made of a conductive oxide such as ITO, but is not limited thereto. The first electrode 20 may be formed by a deposition process such as atomic layer deposition (ALD).

[0035] The hole transport layer may include 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-MeO-TAD), 2,2',7,7'-tetrakis(N,N-di-p-tolyl)amino-9,9-spirobifluorene (Spiro-TTB), polyaniline, polyphenol, poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate, and the like. The hole transport layer 30 may include various P-type organic materials such as poly(4-phenyl)(2,4,6-trimethylphenyl)amine, poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine), poly(PTAA), and poly(3-hexylthiophene-2,5-diyl), or various P-type metal oxides such as Ni oxide, Mo oxide, V oxide, W oxide, or Cu oxide known to those skilled in the art, or various P-type organic or inorganic materials known to those skilled in the art. The hole transport layer 30 may be formed by a deposition process such as CVD (chemical vapor deposition) or ALD (atomic layer deposition).

[0036] The light absorbing layer 40 is made of a perovskite compound.

[0037] The perovskite compound can be obtained by depositing the ABX3 compound by reacting at least one compound selected from amine compounds and amidine compounds, an organic metal compound containing a divalent positive ion, and at least one hydrogen halide via chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0038] In ABX3, A may be composed of a monovalent organic cation of an amine compound, a monovalent organic cation of an amidine compound, or a monovalent organic cation of an amine compound and a monovalent organic cation of an amidine compound. A may have a structure in which a monovalent organic cation of an amine compound is contained in an x ​​ratio and a monovalent organic cation of an amidine compound is contained in an y ratio. In this case, each of x and y is greater than 0, and x+y=1.

[0039] In ABX3, B consists of a divalent positive ion of an organometallic compound.

[0040] In ABX3, X consists of one or more halogen compounds.

[0041] The amine compound may be selected from the group consisting of methylamine, ethylamine and phenethylamine.

[0042] The amidine compound may consist of formamidine.

[0043] The organometallic compound including a divalent positive ion may include a metal selected from the group consisting of lead (Pb), tin (Sn), germanium (Ge), antimony (Sb), bismuth (Bi), and barium (Ba).

[0044] In detail, the organometallic compound including a divalent positive ion may include a compound represented by the following Chemical Formula 1:

[0045] Chemical formula 1

[0046]

[0047] (In Chemical Formula 1, R 1 To R 12 Each independently consists of hydrogen or an alkyl group, and X is selected from the group consisting of Pb, Sn, Ge, Sb, Bi and Ba)

[0048] Alternatively, the organometallic compound containing a divalent cation may be selected from the group consisting of 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 The group composed of N2O2Pb.

[0049] The light absorption rate, optical band gap, carrier mobility and material stability of the finally obtained perovskite compound can be adjusted according to the type of the organic metal compound containing divalent positive ions.

[0050] The hydrohalide may be selected from the group consisting of HI, HBr, HF and HCl. The optical band gap of the finally obtained perovskite compound may be adjusted according to the type of the hydrohalide.

[0051] The amine compound, the amidine compound, the organic metal compound containing a divalent positive ion, and the hydrogen halide include materials that vaporize in the temperature range of room temperature to 200 degrees Celsius (° C.), and preferably, materials that vaporize in the temperature range of 50° C. to 150° C. Therefore, in the process of manufacturing the ABX3 compound, the chemical vapor deposition (CVD) process or the atomic layer deposition (ALD) process can be performed at a temperature of 200° C. or less, preferably, at a temperature of 150° C. or less, so that the organic material in the finally obtained ABX3 compound can be prevented from being decomposed during the CVD process or the ALD process. In addition, plasma can be applied during the CVD process or the ALD process.

[0052] According to another embodiment of the present invention, a perovskite compound can be obtained by depositing a CABX3 compound via chemical vapor deposition (CVD) or atomic layer deposition (ALD) by reacting at least one compound selected from amine compounds and amidine compounds, at least one alkali metal compound, an organic metal compound containing a divalent positive ion and at least one hydrogen halide.

[0053] In CABX3, A may be composed of a monovalent organic cation of an amine compound, a monovalent organic cation of an amidine compound, or a monovalent organic cation of an amine compound and a monovalent organic cation of an amidine compound.

[0054] In CABX3, C may consist of at least one alkali metal compound.

[0055] CA may have a structure in which a monovalent organic positive ion of an amine compound is contained in an x ​​ratio, a monovalent organic positive ion of an amidine compound is contained in an y ratio, and a monovalent positive ion of an alkali metal is contained in an z ratio. In this case, each of x, y, and z is greater than 0, and x+y+z=1.

[0056] In CABX3, B consists of a divalent positive ion, and X consists of one or more halogen components.

[0057] The amine compound, the amidine compound, the organometallic compound containing a divalent positive ion, and the hydrogen halide are as described above, and thus repeated descriptions thereof will be omitted.

[0058] The alkali metal compound may include a compound represented by the following Chemical Formula 2:

[0059] Chemical formula 2

[0060]

[0061] (In Chemical Formula 2, R 1 To R 6 Each independently consists of hydrogen or an alkyl group, and Y is an alkali metal)

[0062] As described above, according to another embodiment of the present invention, at least one alkali metal-based compound may be added to the reactants, thereby compensating for the instability of monovalent organic positive ions that are susceptible to water, heat, and plasma.

[0063] Next, if Figure 1b As shown, an electron transport precursor layer 50 a is formed on the light absorbing layer 40 .

[0064] The electron transport precursor layer 50a may be formed of an inorganic nitride, in particular, an inorganic nitride that does not contain oxygen. Specifically, the electron transport precursor layer 50a may be formed of SnN or ZnN.

[0065] The electron transport precursor layer 50a may be formed of an inorganic sulfide, in particular, an inorganic sulfide that does not contain oxygen. Specifically, the electron transport precursor layer 50a may be formed of SnS, SnS2, or ZnS.

[0066] Inorganic nitrides such as SnN or ZnN may be formed by a deposition process such as CVD or ALD. Since inorganic nitrides such as SnN or ZnN do not contain oxygen, oxidation of the perovskite compound constituting the light absorbing layer 40 may be prevented during the process of forming the electron transport precursor layer 50a.

[0067] Inorganic sulfides such as SnS, SnS2, or ZnS may be formed by a deposition process such as CVD or ALD. Since inorganic sulfides such as SnS, SnS2, or ZnS do not contain oxygen, oxidation of the perovskite compound constituting the light absorbing layer 40 may be prevented during the process of forming the electron transport precursor layer 50a.

[0068] Next, if Figure 1c As shown, oxygen plasma treatment is performed on the electron transport precursor layer 50a.

[0069] Then, oxygen may be injected into the inorganic metal nitride such as SnN or ZnN, and the electron transport precursor layer 50 a may be transformed into 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 .

[0070] Alternatively, oxygen may be injected into an inorganic metal sulfide such as SnS, SnS 2 , or ZnS, and the electron transport precursor layer 50 a may be transformed into 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 .

[0071] The first electron transport layer 51 is a layer that contacts the light absorbing layer 40, and because oxygen is not introduced, the first electron transport layer 51 is made of the same material as the inorganic metal nitride or inorganic metal sulfide constituting the electron transport precursor layer 50a. Therefore, the first electron transport layer 51 may be composed of an inorganic metal nitride that does not contain oxygen (specifically SnN or ZnN), or an inorganic metal sulfide that does not contain oxygen (specifically SnS, SnS2, or ZnS).

[0072] Since inorganic nitrides such as SnN or ZnN and inorganic sulfides such as SnS, SnS2, or ZnS do not contain oxygen, oxidation of the perovskite compound constituting the light absorbing layer provided under the first electron transport layer 51 can be prevented. Therefore, the first electron transport layer 51 including the inorganic nitride or the inorganic sulfide can function as a damage prevention film or barrier film of its underlying layer.

[0073] The second electron transport layer 52 is a layer formed on the first electron transport layer 51 and in contact with the first electron transport layer 51, and oxygen is partially injected into the inorganic metal nitride or inorganic metal sulfide constituting the electron transport precursor layer 50a. Therefore, the second electron transport layer 52 can be made of an inorganic metal nitride oxide (specifically SnON or ZnON), or made of an inorganic metal sulfide oxide (specifically SnOS or ZnOS). The second electron transport layer 52 containing an inorganic metal nitride oxide or an inorganic metal sulfide oxide can act as a damage prevention film or barrier film of its underlying layer.

[0074] The third electron transport layer 53 is a layer formed on the second electron transport layer 52 and in contact with the second electron transport layer 52, and oxygen is injected into the inorganic metal nitride constituting the electron transport precursor layer 50a to replace nitrogen with oxygen, or oxygen is injected into the inorganic metal sulfide constituting the electron transport precursor layer 50a to replace sulfur with oxygen. Therefore, the third electron transport layer 53 can be formed of an inorganic metal oxide (specifically, SnO or ZnO).

[0075] Since the first electron transport layer 51 is composed of an inorganic metal nitride or an inorganic metal sulfide (specifically SnN, ZnN, SnS, SnS2 or ZnS) that does not contain oxygen, oxidation of the perovskite compound constituting the light absorbing layer 40 disposed thereunder can be prevented, but its conductivity is not good.

[0076] On the other hand, the second electron transport layer 52 is made of an inorganic metal oxynitride or an inorganic metal oxysulfide (specifically SnON, ZnON, SnOS or ZnOS) and has excellent conductivity compared to the first electron transport layer 51. Therefore, in order to improve the conductive characteristics, it is desirable that the thickness t2 of the second electron transport layer 52 is thicker than the thickness t1 of the first electron transport layer 51.

[0077] In some cases, the second electron transport layer 52 may not be formed in the process 1c. Specifically, by performing oxygen plasma treatment on the electron transport precursor layer 50a, the second electron transport layer 52 may not be formed on the same first electron transport layer 51 as the electron transport precursor layer 50a, but the third electron transport layer 53 may be directly formed on the first electron transport layer 51.

[0078] For example, the third electron transport layer 53 made of SnO or ZnO may be directly formed on top of the first electron transport layer 51 including an inorganic metal nitride such as SnN or ZnN, or the third electron transport layer 53 made of SnO or ZnO may be directly formed on top of the first electron transport layer 51 including an inorganic metal sulfide such as SnS, SnS2, or ZnS. In this case, the thickness of the third electron transport layer 53 is thicker than that of the first electron transport layer 51.

[0079] Next, if Figure 1d As shown, 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 .

[0080] The transparent conductive layer 60 may include a material having electron transport properties, may include ITO or IZO, but is not limited thereto, and may be formed by a deposition process such as ALD.

[0081] The second electrode 70 may be made of a metal material such as Ag. The second electrode 70 may be patterned into a predetermined shape so that sunlight can enter the cell.

[0082] Figure 2a to Figure 2e is a process diagram for manufacturing a solar cell according to another embodiment of the present invention.

[0083] First, if Figure 2aAs shown, 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 .

[0084] 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 those of the aforementioned embodiment, and thus repeated explanations will be omitted.

[0085] Next, if Figure 2b As shown, an electron transport precursor layer 50 a is formed on the light absorbing layer 40 .

[0086] The specific configurations of the substrate 10 and the electron transport precursor layer 50 a are the same as those of the aforementioned embodiment, and thus repeated explanations will be omitted.

[0087] Next, if Figure 2c As shown, oxygen plasma treatment is performed on the electron transport precursor layer 50a.

[0088] Then, oxygen may be injected into the inorganic metal nitride such as SnN or ZnN, and the electron transport precursor layer 50 a may be transformed into the first electron transport layer 51 and the second electron transport layer 52 .

[0089] Alternatively, oxygen may be injected into an inorganic metal sulfide such as SnS, SnS 2 , or ZnS, and the electron transport precursor layer 50 a may be converted into the first electron transport layer 51 and the second electron transport layer 52 .

[0090] The first electron transport layer 51 is a layer that contacts the light absorbing layer 40, and because oxygen is not introduced, the first electron transport layer 51 is made of the same material as the inorganic metal nitride or inorganic metal sulfide constituting the electron transport precursor layer 50a. Therefore, the first electron transport layer 51 may be composed of an inorganic metal nitride that does not contain oxygen (specifically SnN or ZnN), or an inorganic metal sulfide that does not contain oxygen (specifically SnS, SnS2, or ZnS).

[0091] The second electron transport layer 52 is a layer formed on the first electron transport layer 51, in which oxygen is partially injected into the inorganic metal nitride or inorganic metal sulfide constituting the electron transport precursor layer 50a. Therefore, the second electron transport layer 52 can be made of an inorganic metal nitride oxide (specifically SnON or ZnON), or made of an inorganic metal sulfide oxide (specifically SnOS or ZnOS).

[0092] As in the above embodiment, it is preferred that the thickness t2 of the second electron transport layer 52 is thicker than the thickness t1 of the first electron transport layer 51 .

[0093] In the aforementioned process 1c, by performing oxygen plasma treatment on the electron transport precursor layer 50a, the third electron transport layer 53 is additionally formed on the second electron transport layer 52. However, depending on the process conditions, even if oxygen is injected into the inorganic metal nitride or inorganic metal sulfide constituting the electron transport precursor layer 50a, nitrogen or sulfur may not be replaced by oxygen, so the third electron transport layer 53 may not be formed.

[0094] Next, if Figure 2d As shown, the third electron transport layer 53 is formed on the second electron transport layer 52 to form 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 .

[0095] The third electron transport layer 53 may be formed of an inorganic metal oxide, specifically SnO or ZnO. The third electron transport layer 53 may be formed by a deposition process such as ALD.

[0096] At this time, it is desirable that the thickness t3 of the third electron transport layer 53 is thicker than the thickness t1 of the first electron transport layer 51 to improve the conductive property. In addition, the thickness t3 of the third electron transport layer 53 may be thicker than the thickness t2 of the second electron transport layer 52 .

[0097] In some cases, by omitting the aforementioned process 2c and performing process 2d after the aforementioned process 2b, a third electron transport layer 53 made of an inorganic metal oxide (specifically SnO or ZnO) can be formed on the upper surface of the first electron transport layer 51 made of the electron transport precursor layer 50a.

[0098] Next, if Figure 2e As shown, 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 .

[0099] The specific configurations of the transparent conductive layer 60 and the second electrode 70 are the same as those of the aforementioned embodiment, and thus repeated explanations will be omitted.

[0100] In the above embodiment, the hole transport layer 30 is formed on the lower surface of the light absorption layer 40 , and the electron transport layer 50 is formed on the upper surface of the light absorption layer 40 , which is not necessarily limited thereto.

[0101] The hole transport layer 30 may be formed on the upper surface of the light absorption layer 40 , and the electron transport layer 50 may be formed on the lower surface of the light absorption layer 40 , and such principles also apply to the following embodiments.

[0102] Figure 3a to Figure 3gis a process diagram for manufacturing a solar cell according to another embodiment of the present invention, and relates to a tandem solar cell of a perovskite solar cell and a crystalline solar cell.

[0103] First, if Figure 3a As shown, a crystalline solar cell 100 is manufactured.

[0104] The crystalline solar cell 100 is manufactured by a process of etching one surface and the other surface of a semiconductor substrate 110, such as a wafer, to form a concave-convex structure, doping a specific dopant on the one surface of the semiconductor substrate 110 to form a first semiconductor layer 120, and doping a specific dopant on the other surface of the semiconductor substrate 110 to form a second semiconductor layer 130.

[0105] Since the one surface and the other surface of the semiconductor substrate 110 are formed in the concavo-convex structure, the first semiconductor layer 120 and the second semiconductor layer 130 are formed in shapes corresponding to the concavo-convex structure.

[0106] On the other hand, the drawings show that the one surface and the other surface of the semiconductor substrate 110 are formed as a concavo-convex structure, but it is not necessarily limited thereto. The one surface of the semiconductor substrate 110 may be formed as a concavo-convex structure, and the other surface may be formed as a flat structure. Alternatively, the other surface of the semiconductor substrate 110 may be formed as a concavo-convex structure, and the one surface may be formed as a flat structure. In some cases, the one surface and the other surface of the semiconductor substrate 110 may be formed as a flat structure.

[0107] The semiconductor substrate 110 may be formed of a P-type or N-type wafer, the first semiconductor layer 120 may be doped with a dopant having a different polarity from that of the semiconductor substrate 110, and the second semiconductor layer 130 may be doped with a dopant having the same polarity as that of the semiconductor substrate 110. For example, the semiconductor substrate 110 may be made of a P-type wafer, the first semiconductor layer 120 may be doped with an N-type dopant, and the second semiconductor layer 130 may be doped with a P-type dopant to form a P+ layer.

[0108] Next, if Figure 3b As shown, a buffer layer 200 is formed on the crystalline solar cell 100 .

[0109] The buffer layer 200 is formed on the first semiconductor layer 120. Since the first semiconductor layer 120 is formed in a concavo-convex structure, the buffer layer 200 is formed in a shape corresponding to the concavo-convex structure.

[0110] The buffer layer 200 is disposed between the crystalline solar cell 100 and a perovskite solar cell 300 described below, and thus the solar cell according to the embodiment of the present invention has a structure of a tandem solar cell based on a tunnel junction.

[0111] It is preferable that the buffer layer 200 contains a material for enabling light having a long wavelength to pass through the perovskite solar cell 300 without loss to be incident on the crystalline solar cell 100. For example, the buffer layer 200 may be formed of a transparent conductive oxide, a carbonaceous conductive material, a metallic material, or a conductive polymer, and in some cases, may be doped with an n-type or p-type dopant with the material.

[0112] Next, if Figure 3c As shown, the hole transport layer 30 is formed on the buffer layer 200 , and the light absorption layer 40 is formed on the hole transport layer 30 .

[0113] The specific configurations of the hole transport layer 30 and the light absorption layer 40 are the same as those of the aforementioned embodiment, and thus repeated explanations will be omitted.

[0114] Next, if Figure 3d As shown, an electron transport precursor layer 50 a is formed on the light absorbing layer 40 .

[0115] The specific configuration of the electron transport precursor layer 50 a is the same as that of the aforementioned embodiment, and thus repeated explanation will be omitted.

[0116] Next, if Figure 3e As shown, oxygen plasma treatment is performed on the electron transport precursor layer 50a.

[0117] Then, oxygen is sprayed into an inorganic metal nitride such as SnN or ZnN or an inorganic metal sulfide such as SnS, SnS2 or ZnS so that 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.

[0118] 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 as follows: Figure 1c The specific configuration is the same as in , so repeated description will be omitted.

[0119] Next, if Figure 3f As shown, a transparent conductive layer 60 is formed on the electron transport layer 50 .

[0120] The specific configuration of the transparent conductive layer 60 is the same as that of the aforementioned embodiment, and thus repeated explanation will be omitted.

[0121] Next, if Figure 3g As shown, the first electrode 20 is formed on the bottom surface of the crystalline solar cell 100 , and the second electrode 70 is formed on the top surface of the transparent conductive layer 60 .

[0122] Since the second electrode 70 is formed on the incident surface for incident sunlight, the second electrode 70 is patterned into a predetermined shape. The first electrode 20 may also be configured to allow reflected light of sunlight to enter the solar cell by forming a pattern of a predetermined shape, but is not limited thereto.

[0123] The specific configurations of the first electrode 20 and the second electrode 70 are the same as those of the aforementioned embodiment, and thus repeated explanations will be omitted.

[0124] The first electrode 20 and the second electrode 70 may be formed of various conductive materials known in the art through various pattern forming methods.

[0125] Although not shown in detail, a passivation layer may be formed on the second electrode 70. In this case, a portion of the passivation layer may be etched so that the second electrode 70 may be exposed.

[0126] Figure 4a to Figure 4h is a process diagram for manufacturing a solar cell according to another embodiment of the present invention, and relates to a tandem solar cell of a perovskite solar cell and a crystalline solar cell.

[0127] First, if Figure 4a As shown, a crystalline solar cell 100 is manufactured.

[0128] The crystalline solar cell 100 is manufactured by a process of etching one surface and the other surface of a semiconductor substrate 110, such as a wafer, to form a concave-convex structure, doping a specific dopant on the one surface of the semiconductor substrate 110 to form a first semiconductor layer 120, and doping a specific dopant on the other surface of the semiconductor substrate 110 to form a second semiconductor layer 130.

[0129] Because the specific configuration of the semiconductor substrate 110, the first semiconductor layer 120 and the second semiconductor layer 130 is Figure 3a The specific configurations are the same, so repeated explanations will be omitted.

[0130] Next, if Figure 4b As shown, a buffer layer 200 is formed on the crystalline solar cell 100 .

[0131] Because the specific configuration of the buffer layer 200 is the same as above Figure 3b The specific configuration is the same, so its repeated description will be omitted.

[0132] Next, if Figure 4c As shown, the hole transport layer 30 is formed on the buffer layer 200 , and the light absorption layer 40 is formed on the hole transport layer 30 .

[0133] Because the specific configuration of the hole transport layer 30 and the light absorption layer 40 is Figure 3c The specific configuration is the same, so its repeated description will be omitted.

[0134] Next, if Figure 4d As shown, an electron transport precursor layer 50 a is formed on the light absorbing layer 40 .

[0135] Since the specific configuration of the electron transport precursor layer 50a is the same as that described above Figure 3d The specific configuration is the same, so its repeated description will be omitted.

[0136] Next, if Figure 4e As shown, oxygen plasma treatment is performed on the electron transport precursor layer 50a.

[0137] Then, oxygen is sprayed into an inorganic metal nitride such as SnN or ZnN or an inorganic metal sulfide such as SnS, SnS 2 , or ZnS, so that the electron transport precursor layer 50 a may be transformed into the first electron transport layer 51 and the second electron transport layer 52 .

[0138] Because the specific configurations of the first electron transport layer 51 and the second electron transport layer 52 are the same as those described above Figure 2c The specific configuration is the same, so its repeated description will be omitted.

[0139] Next, if Figure 4f As shown, the third electron transport layer 53 is formed on the second electron transport layer 52 to form 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 .

[0140] Because the specific configuration of the third electron transport layer 53 is the same as above Figure 2d The specific configuration is the same, so its repeated description will be omitted.

[0141] As in the above embodiment, by omitting process 4e and performing process 4f after process 4d, the electron transport layer 50 including the first electron transport layer 51 and the third electron transport layer 53 disposed on the upper surface of the first electron transport layer 51 may be formed.

[0142] Next, if Figure 4g As shown, a transparent conductive layer 60 is formed on the electron transport layer 50 .

[0143] Because the specific configuration of the transparent conductive layer 60 is the same as above Figure 3f The specific configuration is the same, so its repeated description will be omitted.

[0144] Next, if Figure 4h As shown, the first electrode 20 is formed on the bottom surface of the crystalline solar cell 100 , and the second electrode 70 is formed on the top surface of the transparent conductive layer 60 .

[0145] Because the detailed configuration of the first electrode 20 and the second electrode 70 is the same as above Figure 3g The detailed configuration is the same, so its repeated description will be omitted.

[0146] Although not shown in detail, a passivation layer may be formed on the second electrode 70. In this case, a portion of the passivation layer may be etched so that the second electrode 70 may be exposed.

[0147] Figure 5a to Figure 5d is a process diagram for manufacturing a solar cell according to another embodiment of the present invention, Figure 5a to Figure 5d and Figure 1a to Figure 1d The difference is: Figure 5a to Figure 5d A process of forming a passivation layer 80 and an organic material layer 90 is additionally included.

[0148] First, if Figure 5a As shown, a first electrode 20 is formed on a 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 .

[0149] 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 those of the aforementioned embodiment, and thus repeated explanations will be omitted.

[0150] For example, the passivation layer 80 may be formed of an inorganic insulating layer not including oxygen, such as silicon nitride.

[0151] The organic material layer 90 may be formed of fullerene or a fullerene derivative, for example, C60 or phenyl-C61-butyric acid methyl ester (PCBM).

[0152] Next, if Figure 5b As shown, an electron transport precursor layer 50 a is formed on the light absorbing layer 40 .

[0153] Since the specific configuration of the electron transport precursor layer 50a is the same as that described above Figure 1b The specific configuration is the same, so its repeated description will be omitted.

[0154] Next, if Figure 5cAs shown, oxygen plasma treatment is performed on the electron transport precursor layer 50a.

[0155] Then, oxygen may be injected into the inorganic metal nitride such as SnN or ZnN, and the electron transport precursor layer 50 a may be transformed into 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 .

[0156] Alternatively, oxygen may be injected into an inorganic metal sulfide such as SnS, SnS 2 , or ZnS, and the electron transport precursor layer 50 a may be transformed into 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 .

[0157] The specific configurations of the first electron transport layer 51, the second electron transport layer 52 and the third electron transport layer 53 are as follows: Figure 1c The specific configuration is the same, so its repeated description will be omitted.

[0158] In this case, the first electron transport layer 51 and the second electron transport layer 52 may function as a damage prevention film or a barrier film that prevents the passivation layer 80 and the organic material layer 90 from being damaged.

[0159] Next, if Figure 5d As shown, 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 .

[0160] Because the specific configuration of the transparent conductive layer 60 and the second electrode 70 is the same as above Figure 1d The specific configuration is the same, so its repeated description will be omitted.

[0161] Although not specifically shown, according to Figure 2a to Figure 2e The above-mentioned embodiment may also additionally include a process of forming a passivation layer 80 and an organic material layer 90. In other words, in the above-mentioned Figure 2a In the process, a passivation layer 80 and an organic material layer 90 may be sequentially formed on the light absorbing layer 40, and then Figure 2b In the process of forming an electron transport precursor layer 50 a on the organic material layer 90 .

[0162] In addition, the process of forming the passivation layer 80 and the organic material layer 90 may be additionally included in the above-mentioned Figure 3a to Figure 3g In other words, in the aforementioned Figure 3c In the process, a passivation layer 80 and an organic material layer 90 may be sequentially formed on the light absorbing layer 40, and then Figure 3d In the process of forming an electron transport precursor layer 50 a on the organic material layer 90 .

[0163] In addition, the process of forming the passivation layer 80 and the organic material layer 90 may be additionally included in the above-mentioned Figure 4a to Figure 4h In other words, in the aforementioned Figure 4c In the process, a passivation layer 80 and an organic material layer 90 may be sequentially formed on the light absorbing layer 40, and then Figure 4d In the process of forming an electron transport precursor layer 50 a on the organic material layer 90 .

[0164] Above, the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, but the present invention is not limited to these embodiments and can be modified in various ways without departing from the technical spirit of the present invention. Therefore, it should be understood that the above embodiments are only exemplary and non-restrictive in all aspects. It should be explained that the scope of the present invention is defined by the following claims rather than by the embodiments, and the scope and meaning of the claims and all changes and modifications derived from the concepts equivalent to the claims are included in the scope of the present invention.

Claims

1. A solar cell comprising: a light absorbing layer comprising a perovskite compound; as well as An electron transport layer is disposed on the first surface of the light absorbing layer, wherein the electron transport layer comprises a first electron transport layer disposed on the first surface of the light absorbing layer and a second electron transport layer disposed on the first electron transport layer, and The first electron transport layer comprises an inorganic metal nitride and the second electron transport layer comprises an inorganic metal oxynitride, or the first electron transport layer comprises an inorganic metal sulfide and the second electron transport layer comprises an inorganic metal oxysulfide.

2. The solar cell according to claim 1, wherein: The first electron transport layer comprises SnN and the second electron transport layer comprises SnON, or The first electron transport layer comprises ZnN and the second electron transport layer comprises ZnON, or The first electron transport layer comprises SnS or SnS2 and the second electron transport layer comprises SnOS, or The first electron transport layer includes ZnS and the second electron transport layer includes ZnOS. 3 . The solar cell of claim 1 , further comprising a passivation layer between the light absorbing layer and the electron transporting layer. 4 . The solar cell according to claim 3 , further comprising an organic material layer between the passivation layer and the electron transport layer.

5. The solar cell according to claim 1, wherein: The second electron transport layer is thicker than the first electron transport layer.

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

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

8. A solar cell comprising: a light absorbing layer comprising a perovskite compound; as well as an electron transport layer, disposed on the first surface of the light absorbing layer, wherein the electron transport layer comprises a first electron transport layer disposed on the first surface of the light absorbing layer and a third electron transport layer disposed on the first electron transport layer, and Wherein, the first electron transport layer comprises an inorganic metal nitride or an inorganic metal sulfide, and the third electron transport layer comprises an inorganic metal oxide.

9. The solar cell according to claim 8, wherein: The first electron transport layer comprises SnN, SnS or SnS2, and the third electron transport layer comprises SnO, or The first electron transport layer includes ZnN or ZnS, and the third electron transport layer includes ZnO.

10. The solar cell according to claim 8, wherein: The third electron transport layer is thicker than the first electron transport layer. 11 . The solar cell according to claim 8 , further comprising a passivation layer between the light absorbing layer and the electron transporting layer, and an organic material layer between the passivation layer and the electron transporting layer.

12. The solar cell according to claim 8, further comprising a transparent conductive layer located on the electron transport layer, wherein: The transparent conductive layer includes a material having electron transport properties. 13 . The solar cell according to claim 8 , further comprising a buffer layer on the second surface of the light absorbing layer and a crystalline solar cell on the buffer layer. 14 . The solar cell of claim 1 , further comprising a buffer layer on the second surface of the light absorbing layer and a crystalline solar cell on the buffer layer.

15. A method for manufacturing a solar cell, comprising: forming a light absorbing layer including a perovskite compound; as well as forming an electron transport layer on the first surface of the light absorbing layer, Wherein, forming the electron transport layer comprises: forming an electron transport precursor layer comprising an inorganic metal nitride or an inorganic metal sulfide; and Oxygen plasma treatment is performed on the electron transport precursor layer to form a first electron transport layer including an inorganic metal nitride or an inorganic metal sulfide and a second electron transport layer including an inorganic metal oxynitride or an inorganic metal oxysulfide.

16. The method for manufacturing a solar cell according to claim 15, wherein: The electron transport precursor layer and the first electron transport layer comprise SnN and the second electron transport layer comprises SnON, or The electron transport precursor layer and the first electron transport layer comprise ZnN and the second electron transport layer comprises ZnON, or The electron transport precursor layer and the first electron transport layer comprise SnS or SnS2 and the second electron transport layer comprises SnOS, or The electron transport precursor layer and the first electron transport layer include ZnS and the second electron transport layer includes ZnOS.

17. The method for manufacturing a solar cell according to claim 15, further comprising: A third electron transport layer including an inorganic metal oxide is formed on the second electron transport layer, wherein the third electron transport layer includes SnO or ZnO.

18. The method for manufacturing a solar cell according to claim 15, further comprising: A passivation layer is formed between the light absorbing layer and the electron transporting layer, and an organic material layer is formed between the passivation layer and the electron transporting layer.

19. A method for manufacturing a solar cell, comprising: forming a light absorbing layer including a perovskite compound; as well as forming an electron transport layer on the first surface of the light absorbing layer, Wherein, forming the electron transport layer comprises: forming an electron transport precursor layer comprising an inorganic metal nitride or an inorganic metal sulfide; and Oxygen plasma treatment is performed on the electron transport precursor layer to form a first electron transport layer including an inorganic metal nitride or an inorganic metal sulfide and a third electron transport layer including an inorganic metal oxide.

20. The method for manufacturing a solar cell according to claim 19, wherein: The first electron transport layer comprises SnN, SnS or SnS2, and the third electron transport layer comprises SnO, or The first electron transport layer includes ZnN or ZnS, and the third electron transport layer includes ZnO.

21. The method for manufacturing a solar cell according to claim 19, further comprising: A passivation layer is formed between the light absorbing layer and the electron transporting layer, and an organic material layer is formed between the passivation layer and the electron transporting layer.

22. The method for manufacturing a solar cell according to claim 19, further comprising: A transparent conductive layer is formed on the electron transport layer, wherein the transparent conductive layer contains a material having electron transport properties.

23. The method for manufacturing a solar cell according to claim 19, further comprising: Before forming the light absorbing layer, a crystalline solar cell is formed and a buffer layer is formed on the crystalline solar cell, wherein the light absorbing layer is disposed on the buffer layer.

24. The method for manufacturing a solar cell according to claim 15, further comprising: Before forming the light absorbing layer, a crystalline solar cell is formed and a buffer layer is formed on the crystalline solar cell, wherein the light absorbing layer is disposed on the buffer layer.

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