Solar cell and its manufacturing method

Abstract

The present invention provides a solar cell including a semiconductor substrate, a first semiconductor layer provided on one side of the semiconductor substrate, a second semiconductor layer provided on one side of the first semiconductor layer, a third semiconductor layer provided on one side of the second semiconductor layer, a first transparent conductive layer provided on one side of the third semiconductor layer, and a first electrode provided on one side of the first transparent conductive layer, wherein the second semiconductor layer is a p-type semiconductor layer and the third semiconductor layer is a p+-type semiconductor layer containing W, and a method for manufacturing the solar cell.

Description

[Technical Field]

[0001] The present invention relates to a solar cell, and more particularly to a solar cell using a semiconductor substrate. [Background technology]

[0002] Solar cells using semiconductor substrates are manufactured by forming a plurality of semiconductor layers on a semiconductor substrate.

[0003] For example, a conventional solar cell includes a p-type semiconductor layer formed on one side of a semiconductor substrate, an n-type semiconductor layer formed on the other side of the semiconductor substrate, and a transparent conductive layer formed on the p-type semiconductor layer.

[0004] In conventional solar cells, a p-type amorphous silicon layer is used as the p-type semiconductor layer, but in this case, there is a problem that the band gap of p-type amorphous silicon is large, resulting in a low open-circuit voltage (Voc) of the solar cell. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been devised to solve the above-mentioned conventional problems, and aims to provide a solar cell and a manufacturing method thereof that can increase the open circuit voltage by further forming a p+ type semiconductor layer between a p type semiconductor layer and a transparent conductive layer. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides a solar cell comprising a semiconductor substrate, a first semiconductor layer provided on one side of the semiconductor substrate, a second semiconductor layer provided on one side of the first semiconductor layer, a third semiconductor layer provided on one side of the second semiconductor layer, a first transparent conductive layer provided on one side of the third semiconductor layer, and a first electrode provided on one side of the first transparent conductive layer, wherein the second semiconductor layer comprises a p-type semiconductor material and the third semiconductor layer comprises a p-type semiconductor material containing W.

[0007] The band gap of the third semiconductor layer may be smaller than the band gap of the second semiconductor layer, and the maximum energy level of a valence band of the third semiconductor layer may be lower than the maximum energy level of a valence band of the second semiconductor layer.

[0008] The first transparent conductive layer may be made of a transparent oxide film containing indium.

[0009] The first semiconductor layer may be an intrinsic amorphous silicon layer.

[0010] The semiconductor device may further include a fourth semiconductor layer provided on the other side of the semiconductor substrate, a fifth semiconductor layer provided on the other side of the fourth semiconductor layer, a second transparent conductive layer provided on the other side of the fifth semiconductor layer, and a second electrode provided on the other side of the second transparent conductive layer, and the fifth semiconductor layer may comprise an n-type semiconductor material including Sn.

[0011] The fourth semiconductor layer may be an intrinsic amorphous silicon layer, and an n-type amorphous silicon layer may be further provided between the fourth semiconductor layer and the fifth semiconductor layer, the band gap of the fifth semiconductor layer may be larger than the band gap of the n-type amorphous silicon layer, and the minimum energy level of the conduction band of the fifth semiconductor layer may be higher than the minimum energy level of the conduction band of the n-type amorphous silicon layer.

[0012] The fifth semiconductor layer may be formed to a thickness in the range of 10 Å to 100 Å, and the second transparent conductive layer may be formed to a thickness in the range of 100 Å to 500 Å.

[0013] The second transparent conductive layer may be made of a transparent oxide film containing indium, and the concentration of indium in the transparent oxide film may be in the range of 1 atomic % to 5 atomic %.

[0014] The first transparent conductive layer may be made of a transparent oxide film containing indium, and the content of indium contained in the first transparent conductive layer may be higher than the content of indium contained in the second transparent conductive layer.

[0015] The solar cell may further include a perovskite solar cell provided between the second transparent conductive layer and the second electrode, and the perovskite solar cell may include a first conductive charge transfer layer made of a hole transport layer in contact with the second transparent conductive layer, a light absorbing layer made of a perovskite compound provided on the first conductive charge transfer layer, and a second conductive charge transfer layer made of an electron transport layer provided on the light absorbing layer.

[0016] The present invention also provides a method for manufacturing a solar cell, comprising the steps of: forming a first semiconductor layer on one side of a semiconductor substrate; forming a second semiconductor layer on one side of the first semiconductor layer; forming a third semiconductor layer on one side of the second semiconductor layer; forming a first transparent conductive layer on one side of the third semiconductor layer; and forming a first electrode on the first transparent conductive layer, wherein the step of forming the third semiconductor layer comprises forming a p-type semiconductor material containing W, and the steps of forming the third semiconductor layer and the first transparent conductive layer are successive steps carried out in the same processing equipment.

[0017] The step of forming the first transparent conductive layer may include a step of forming a transparent oxide film containing indium.

[0018] The method may further include the steps of forming a fourth semiconductor layer on the other side of the semiconductor substrate, forming a fifth semiconductor layer on the other side of the fourth semiconductor layer, forming a second transparent conductive layer on the other side of the fifth semiconductor layer, and forming a second electrode on the other side of the second transparent conductive layer, wherein the step of forming the fifth semiconductor layer includes the step of forming an n-type semiconductor material containing Sn, and the steps of forming the fifth semiconductor layer and the second transparent conductive layer may be continuous processes performed in the same process equipment.

[0019] The step of forming the fifth semiconductor layer can include a step of forming SnO by introducing a material containing Sn and a material containing O into a chamber, and the step of forming the second transparent conductive layer can include a step of forming a transparent oxide film containing indium by introducing the material containing Sn, the material containing O, and a material containing indium into the chamber.

[0020] The forming of the fifth semiconductor layer and the forming of the second transparent conductive layer may include the steps of: introducing a material containing Sn and a material containing O into a chamber to form an SnO layer; and further doping the SnO layer with indium, thereby forming the fifth semiconductor layer made of an SnO layer that is not doped with indium; and the second transparent conductive layer made of a transparent oxide film that is doped with indium and contains the indium.

[0021] The method may further include forming an n-type amorphous silicon layer between the fourth semiconductor layer forming process and the fifth semiconductor layer forming process, and the fourth semiconductor layer forming process and the n-type amorphous silicon layer forming process may be continuous processes performed in the same processing equipment.

[0022] The method may further include a step of forming a perovskite solar cell between the second transparent conductive layer and the second electrode, and the step of forming the perovskite solar cell may include a step of forming a first conductive charge transfer layer made of a hole transport layer in contact with the second transparent conductive layer, a step of forming a light absorbing layer made of a perovskite compound on the first conductive charge transfer layer, and a step of forming a second conductive charge transfer layer made of an electron transport layer on the light absorbing layer. [Effects of the Invention]

[0023] According to the present invention as described above, the following effects are obtained.

[0024] According to one embodiment of the present invention, the open circuit voltage of the solar cell can be increased by further forming a p+ type semiconductor layer containing W between the second semiconductor layer made of a p-type semiconductor layer and the first transparent conductive layer.

[0025] Furthermore, according to one embodiment of the present invention, the third semiconductor layer contains WO3 and the first transparent conductive layer contains indium-doped WO3, which has the advantage that the third semiconductor layer and the first transparent conductive layer can be formed in a continuous process within the same processing equipment.

[0026] In addition, according to one embodiment of the present invention, since the fifth semiconductor layer made of an n-type semiconductor layer contains SnO having a wide band gap, the open circuit voltage of the solar cell can be increased. Furthermore, since the second transparent conductive layer formed on the fifth semiconductor layer contains SnO doped with indium, there is an advantage that the fifth semiconductor layer and the second transparent conductive layer can be formed in a continuous process in the same device.

[0027] Furthermore, according to one embodiment of the present invention, since the fifth semiconductor layer made of an n-type semiconductor layer contains SnO having excellent electrical conductivity, it is possible to prevent the problem of increased electrical resistance even if the thickness of the second transparent conductive layer formed on the fifth semiconductor layer is reduced. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a cross-sectional view of a solar cell according to one embodiment of the present invention. [Figure 2] 1 is a cross-sectional view of a solar cell according to another embodiment of the present invention. [Figure 3] 10 is a cross-sectional view of a solar cell according to still another embodiment of the present invention. [Figure 4] 10 is a cross-sectional view of a solar cell according to still another embodiment of the present invention. [Figure 5A] FIG. 5A is a cross-sectional view showing a manufacturing process of a solar cell according to an embodiment of the present invention. [Figure 5B] FIG. 5B is a cross-sectional view showing a manufacturing process of a solar cell according to an embodiment of the present invention. [Figure 5C] FIG. 5C is a cross-sectional view showing a manufacturing process of a solar cell according to an embodiment of the present invention. [Figure 6A] FIG. 6A is a cross-sectional view showing a manufacturing process of a solar cell according to another embodiment of the present invention. [Figure 6B] FIG. 6B is a cross-sectional view showing a manufacturing process of a solar cell according to another embodiment of the present invention. [Figure 6C] FIG. 6C is a cross-sectional view showing a manufacturing process of a solar cell according to another embodiment of the present invention. [Figure 7A] FIG. 7A is a cross-sectional view showing a manufacturing process of a solar cell according to still another embodiment of the present invention. [Figure 7B] FIG. 7B is a cross-sectional view showing a manufacturing process of a solar cell according to still another embodiment of the present invention. [Figure 7C] FIG. 7C is a cross-sectional view showing a manufacturing process of a solar cell according to still another embodiment of the present invention. [Figure 7D] FIG. 7D is a cross-sectional view showing a manufacturing process of a solar cell according to still another embodiment of the present invention. [Figure 8A] FIG. 8A is a cross-sectional view showing a manufacturing process of a solar cell according to still another embodiment of the present invention. [Figure 8B] FIG. 8B is a cross-sectional view showing a manufacturing process of a solar cell according to still another embodiment of the present invention. [Figure 8C] FIG. 8C is a cross-sectional view showing a manufacturing process of a solar cell according to still another embodiment of the present invention. [Figure 8D]FIG. 8D is a cross-sectional view showing a manufacturing process of a solar cell according to still another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] The advantages and features of the present invention, as well as methods for achieving them, will become more apparent from the following detailed description of the embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be embodied in various different forms. These embodiments are provided solely to ensure that the disclosure of the present invention is complete and to fully convey the scope of the invention to those skilled in the art. The present invention is defined only by the claims.

[0030] The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for illustrating the embodiments of the present invention are merely examples, and the present invention is not limited to the details shown in the drawings. The same reference numerals refer to the same elements throughout the specification. Furthermore, in describing the present invention, if a detailed description of related prior art is deemed to unnecessarily obscure the gist of the present invention, such a detailed description will be omitted. When "comprises," "has," "consists of," etc. are used in the present invention, other parts may be added unless "only" is used. When an element is expressed in the singular, the plural is also included unless otherwise explicitly stated.

[0031] When interpreting elements, it is understood that a margin of error is included unless otherwise expressly stated.

[0032] When describing a positional relationship, for example, when describing the positional relationship of two parts using "above," "on top," "below," or "beside," one or more other parts may be located between the two parts, unless "immediately" or "directly" is used.

[0033] When describing a temporal relationship, for example, when the temporal precedence is described using "after," "following," "next to," or "before," non-consecutive cases can also be included, unless "immediately" or "directly" is used.

[0034] Although terms such as "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another. Therefore, a "first" component referred to below may also be a "second" component within the technical spirit of the present invention.

[0035] The features of the various embodiments of the present invention may be partially or fully combined or combined with each other, and may be technically interlocked and driven in various ways, and each embodiment may be implemented independently of the others or may be implemented together in a linked relationship.

[0036] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0037] FIG. 1 is a cross-sectional view of a solar cell according to one embodiment of the present invention.

[0038] As can be seen from FIG. 1, a solar cell according to one embodiment of the present invention comprises a semiconductor substrate 100, a first semiconductor layer 210, a second semiconductor layer 220, a third semiconductor layer 230, a fourth semiconductor layer 240, a fifth semiconductor layer 250, a first transparent conductive layer 310, a second transparent conductive layer 320, a first electrode 410, and a second electrode 420.

[0039] The semiconductor substrate 100 may be an n-type semiconductor wafer. One side and the other side of the semiconductor substrate 100, specifically the bottom and top sides, may be formed with an uneven structure. Thus, a number of layers stacked on one side of the semiconductor substrate 100 and a number of layers stacked on the other side of the semiconductor substrate 100 may be stacked with an uneven structure corresponding to the uneven structure of the semiconductor substrate 100. However, it is also possible to form an uneven structure on only one of the one side and the other side of the semiconductor substrate 100, or to not form an uneven structure on both the one side and the other side of the semiconductor substrate 100.

[0040] The first semiconductor layer 210 is formed on one surface, for example, the bottom surface, of the semiconductor substrate 100. The first semiconductor layer 210 is formed by a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD), and may be an intrinsic semiconductor layer, for example, an intrinsic amorphous silicon layer. However, in some cases, the first semiconductor layer 210 may be a semiconductor layer doped with a trace amount of dopant, for example, a trace amount of p-type dopant, particularly an amorphous silicon layer doped with a trace amount of p-type dopant.

[0041] The second semiconductor layer 220 is formed on one surface, for example, the bottom surface, of the first semiconductor layer 210. The second semiconductor layer 220 may be formed through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD) and may be a semiconductor layer doped with a predetermined dopant. In particular, the second semiconductor layer 220 may be a p-type semiconductor layer, particularly a p-type amorphous silicon layer, doped with a p-type dopant having a polarity different from that of the semiconductor substrate 100.

[0042] The third semiconductor layer 230 is formed on one surface, for example, the lower surface, of the second semiconductor layer 220. The third semiconductor layer 230 is a p+ type semiconductor layer formed through a thin film deposition process. In particular, the third semiconductor layer 230 is a p-type semiconductor material containing W, specifically WO3, formed using an atomic layer deposition method. をThe band gap of WO3 is smaller than that of the p-type amorphous silicon constituting the second semiconductor layer 220. In addition, the work function of WO3 is larger than that of the p-type amorphous silicon constituting the second semiconductor layer 220. In addition, the maximum energy level of the valence band of WO3 is lower than that of the p-type amorphous silicon layer. Therefore, when WO3 is used as the material for the third semiconductor layer 230, it is advantageous in that the open-circuit voltage (Voc) of the solar cell can be increased.

[0043] The third semiconductor layer 230 may further contain a p-type dopant such as Ti or H, thereby reducing the interface resistance and bulk resistance of the third semiconductor layer 230 and improving charge mobility, thereby improving the efficiency of the solar cell.

[0044] The fourth semiconductor layer 240 is formed on the other surface, e.g., the top surface, of the semiconductor substrate 100. The fourth semiconductor layer 240 is formed through a thin film deposition process and may be an intrinsic semiconductor layer, e.g., an intrinsic amorphous silicon layer. However, in some cases, the fourth semiconductor layer 240 may be an amorphous silicon layer doped with a small amount of dopant, e.g., a small amount of n-type dopant. Here, the polarity of the dopant doped in the fourth semiconductor layer 240 is opposite to the polarity of the dopant doped in the first semiconductor layer 210.

[0045] The fifth semiconductor layer 250 is formed on the other surface, for example, the upper surface, of the fourth semiconductor layer 240. The fifth semiconductor layer 250 may be formed through a thin film deposition process and may be a semiconductor layer doped with a predetermined dopant. Here, the polarity of the dopant doped in the fifth semiconductor layer 250 is opposite to the polarity of the dopant doped in the second semiconductor layer 220.

[0046] According to an embodiment of the present invention, the fifth semiconductor layer 250 may be an n-type amorphous silicon layer formed by a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0047] Meanwhile, according to another embodiment of the present invention, the fifth semiconductor layer 250 may include an n-type semiconductor material containing Sn, specifically SnO, formed using atomic layer deposition (ALD). Since SnO is an n-type semiconductor material with excellent electrical conductivity, when the fifth semiconductor layer 250 includes SnO, there is an advantage in that the thickness of the second transparent conductive layer 320 formed on the fifth semiconductor layer 250 can be reduced.

[0048] Although materials such as Al, Ag, and LiF can be used as the material for the fifth semiconductor layer 250, SnO has a wider band gap than Al, Ag, and LiF, and therefore, when the fifth semiconductor layer 250 is made of SnO, it has the advantage of being able to increase the open-circuit voltage (Voc) of the solar cell. Meanwhile, Cs2CO3 has an even wider energy band gap than SnO, so it is also possible to use Cs2CO3 for the fifth semiconductor layer 250, but forming the fifth semiconductor layer 250 from SnO has the advantage that the second transparent conductive layer 320 can be formed from ITO by simply adding indium in the same processing equipment.

[0049] The fifth semiconductor layer 250 may further contain an n-type dopant such as In, F, or Zn, thereby reducing the interface resistance and bulk resistance of the fifth semiconductor layer 250 and improving charge mobility, thereby improving the efficiency of the solar cell.

[0050] The thickness of the fifth semiconductor layer 250 is preferably in the range of 10 Å to 100 Å. If the thickness of the fifth semiconductor layer 250 is less than 10 Å, charge transfer within the fifth semiconductor layer 250 may be inhibited, and if the thickness of the fifth semiconductor layer 250 exceeds 100 Å, the transmittance of the fifth semiconductor layer 250 may be reduced.

[0051] The first transparent conductive layer 310 is formed on one surface, for example, the bottom surface, of the third semiconductor layer 230. The first transparent conductive layer 310 is formed through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD). In particular, the first transparent conductive layer 310 may be made of a transparent oxide film containing indium, specifically, indium-doped WO3. In this case, there is an advantage that the third semiconductor layer 230 and the first transparent conductive layer 310 can be formed in succession in the same process equipment.

[0052] The first transparent conductive layer 310 is formed on the surface opposite to the sunlight incident surface, and therefore, its thickness can be formed with greater consideration given to electrical conductivity rather than light transmittance. Therefore, the thickness of the first transparent conductive layer 310 can be formed thicker than the thickness of the second transparent conductive layer 320. Furthermore, when the first transparent conductive layer 310 is made of indium-doped WO3, increasing the indium content can decrease transmittance but improve electrical conductivity. As described above, since the first transparent conductive layer 310 can be formed with greater consideration given to electrical conductivity rather than transmittance, increasing the indium content in the first transparent conductive layer 310 is preferable for improving electrical conductivity. Therefore, the indium content in the first transparent conductive layer 310 can be greater than the indium content in the second transparent conductive layer 320, which will be described later.

[0053] The second transparent conductive layer 320 is formed on the other surface, for example, the upper surface, of the fifth semiconductor layer 250 .

[0054] The second transparent conductive layer 320 is formed through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0055] As described above, since the fifth semiconductor layer 250 has excellent electrical conductivity, the second transparent conductive layer 320 can be formed to have a thin thickness, and more specifically, the second transparent conductive layer 320 can be formed to have a thickness in the range of 100 Å to 500 Å. If the thickness of the second transparent conductive layer 320 is less than 100 Å, the resistance of the second transparent conductive layer 320 may be high, and if the thickness of the second transparent conductive layer 320 is more than 500 Å, the transmittance of the second transparent conductive layer 320 may be reduced.

[0056] The second transparent conductive layer 320 may be made of a transparent oxide film containing indium, for example, ITO, so that the fifth semiconductor layer 250 and the second transparent conductive layer 320 can be formed by a continuous process in the same process equipment, as described above.

[0057] When the second transparent conductive layer 320 is made of a transparent oxide film containing indium, the indium concentration in the transparent oxide film is preferably in the range of 1 atomic % to 5 atomic %. If the indium concentration in the transparent oxide film is less than 1 atomic %, the electrical conductivity of the second transparent conductive layer 320 may decrease, and if the indium concentration in the transparent oxide film is more than 5 atomic %, the transmittance of the second transparent conductive layer 320 may decrease.

[0058] Furthermore, the concentration of indium in the second transparent conductive layer 320 may not be constant. In particular, the concentration of indium at the upper surface of the second transparent conductive layer 320 may be greater than the concentration of indium at the lower surface of the second transparent conductive layer 320, and in particular, the concentration of indium may gradually increase from the lower surface of the second transparent conductive layer 320 to the upper surface of the second transparent conductive layer 320.

[0059] The first electrode 410 is formed on one surface, for example, the lower surface, of the first transparent conductive layer 310 .

[0060] The first electrode 410 is formed on the surface opposite to the solar light incident surface, and may be formed on the entire lower surface of the first transparent conductive layer 310. However, the first electrode 410 may be patterned into a predetermined shape so that reflected sunlight can be incident into the solar cell through the first transparent conductive layer 310. The first electrode 410 may be made of various metal materials known in the art and may be formed by various patterning processes known in the art, such as screen printing.

[0061] The second electrode 420 is formed on the other surface, for example, the upper surface, of the second transparent conductive layer 320 .

[0062] The second electrode 420 is formed on an incident surface where sunlight is incident, and therefore, the second electrode 420 is patterned in a predetermined shape to prevent a reduction in the amount of incident sunlight due to the second electrode 420. The second electrode 420 may be made of various metal materials known in the art and may be formed by various pattern forming processes known in the art, such as screen printing.

[0063] FIG. 2 is a cross-sectional view of a solar cell according to another embodiment of the present invention.

[0064] As can be seen from FIG. 2, a solar cell according to another embodiment of the present invention comprises a semiconductor substrate 100, a first semiconductor layer 210, a second semiconductor layer 220, a third semiconductor layer 230, a fourth semiconductor layer 240, a fifth semiconductor layer 250, a sixth semiconductor layer 260, a first transparent conductive layer 310, a second transparent conductive layer 320, a first electrode 410, and a second electrode 420.

[0065] The solar cell according to another embodiment of the present invention shown in Figure 2 is the same as the solar cell according to Figure 1, except for the addition of a sixth semiconductor layer 260. Therefore, the same reference numerals are used to refer to the same components, and only the different components will be described below.

[0066] 2, according to another embodiment of the present invention, a sixth semiconductor layer 260 is further formed between the fourth semiconductor layer 240 and the fifth semiconductor layer 250. That is, the sixth semiconductor layer 260 is formed between the upper surface of the fourth semiconductor layer 240 and the lower surface of the fifth semiconductor layer 250.

[0067] The sixth semiconductor layer 260 may be formed through a thin film deposition process and may be a semiconductor layer doped with a dopant of the same polarity as the fifth semiconductor layer 250, for example, an n-type dopant. The sixth semiconductor layer 260 is preferably made of a material having a smaller bandgap than the fifth semiconductor layer 250 made of SnO. Specifically, the sixth semiconductor layer 260 may be made of an n-type amorphous silicon layer. The fifth semiconductor layer 250 made of SnO may have a lower work function than the sixth semiconductor layer 260 made of n-type amorphous silicon. The fifth semiconductor layer 250 made of SnO preferably has a higher conduction band minimum energy level than the sixth semiconductor layer 260 made of n-type amorphous silicon. In this case, the fifth semiconductor layer 250 made of SnO constitutes an n+ type semiconductor layer. When the sixth semiconductor layer 260 is made of an n-type amorphous silicon layer, the interface characteristics between the fourth semiconductor layer 240 and the fifth semiconductor layer 250 can be improved.

[0068] FIG. 3 is a cross-sectional view of a solar cell according to yet another embodiment of the present invention.

[0069] As can be seen from FIG. 3 , the solar cell according to another embodiment of the present invention comprises a semiconductor substrate 100, a first semiconductor layer 210, a second semiconductor layer 220, a third semiconductor layer 230, a fourth semiconductor layer 240, a fifth semiconductor layer 250, a first transparent conductive layer 310, a second transparent conductive layer 320, a first electrode 410, a second electrode 420, and a perovskite solar cell 500.

[0070] The solar cell according to another embodiment of the present invention shown in Figure 3 is the same as the solar cell according to Figure 1, except for the addition of a perovskite solar cell 500. Therefore, the same reference numerals are used to refer to the same components, and only the different components will be described below.

[0071] As can be seen from FIG. 3, according to another embodiment of the present invention, a perovskite solar cell 500 is further formed between the second transparent conductive layer 320 and the second electrode 420 in the structure of FIG. 1 described above.

[0072] Therefore, a solar cell according to another embodiment of the present invention is a tandem-structure solar cell including a substrate-type solar cell including the semiconductor substrate 100, the first semiconductor layer 210, the second semiconductor layer 220, the third semiconductor layer 230, the fourth semiconductor layer 240, the fifth semiconductor layer 250, the first transparent conductive layer 310, and the second transparent conductive layer 320, and the perovskite solar cell 500 formed on the substrate-type solar cell.

[0073] Here, the second transparent conductive layer 320 can function as a buffer layer between the substrate-type solar cell and the perovskite solar cell 500, and no separate buffer layer is required.

[0074] The perovskite solar cell 500 includes conductive charge transfer layers 520, 530 and a light absorbing layer 510.

[0075] The perovskite solar cell 500 may include one or more conductive charge transfer layers 520, 530. For example, the perovskite solar cell 500 may include a first conductive charge transfer layer 520 on the second transparent conductive layer 320 and in contact with the second transparent conductive layer 320, a light absorbing layer 510 provided on the first conductive charge transfer layer 520, and a second conductive charge transfer layer 530 provided on the light absorbing layer 510. However, the present invention is not limited thereto, and the conductive charge transfer layers 520, 530 may be disposed on only one of both sides of the light absorbing layer 510.

[0076] The first conductive charge transfer layer 520 may be configured to have a different polarity, for example, p-type polarity, from the fifth semiconductor layer 250, and the second conductive charge transfer layer 530 may be configured to have a different polarity, for example, n-type polarity, from the first conductive charge transfer layer 520. Therefore, the first conductive charge transfer layer 520 may be a hole-transporting layer (HTL), and the second conductive charge transfer layer 530 may be an electron transporting layer (ETL).

[0077] The hole transport layer may be comprised of various p-type organic materials known in the art, such as Spiro-MeO-TAD, Spiro-TTB, polyaniline, polyvinyl alcohol, poly-3,4-ethylenedioxythiophene-polystyrene sulfonate (PEDOT-PSS), poly-[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly(3-hexylthiophene-2,5-diyl) (P3HT), etc., or may be comprised of various p-type metal oxides known in the art, such as Ni oxide, Mo oxide, V oxide, W oxide, Cu oxide, etc., in addition to various p-type organic or inorganic compounds.

[0078] The electron transport layer may be composed of n-type organic materials such as BCP (Bathocuproine), C60, or PCBM (Phenyl-C61-butyric acid methyl ester), or various n-type metal oxides known in the art such as ZnO, c-TiO2 / mp-TiO2, SnO2, or IZO, as well as various n-type organic or inorganic compounds.

[0079] The light absorbing layer 510 is made of a perovskite compound known in the art.

[0080] FIG. 4 is a cross-sectional view of a solar cell according to yet another embodiment of the present invention.

[0081] As can be seen from FIG. 4 , a solar cell according to another embodiment of the present invention comprises a semiconductor substrate 100, a first semiconductor layer 210, a second semiconductor layer 220, a third semiconductor layer 230, a fourth semiconductor layer 240, a fifth semiconductor layer 250, a sixth semiconductor layer 260, a first transparent conductive layer 310, a second transparent conductive layer 320, a first electrode 410, a second electrode 420, and a perovskite solar cell 500.

[0082] The solar cell according to another embodiment of the present invention shown in Figure 4 is the same as the solar cell according to Figure 2, except for the addition of a perovskite solar cell 500. Therefore, the same reference numerals are used to denote the same components, and only the different components will be described below.

[0083] As can be seen from FIG. 4, according to another embodiment of the present invention, a perovskite solar cell 500 is further formed between the second transparent conductive layer 320 and the second electrode 420 in the structure of FIG. 2 described above.

[0084] Therefore, a solar cell according to another embodiment of the present invention is a tandem-structure solar cell including a substrate-type solar cell including the semiconductor substrate 100, the first semiconductor layer 210, the second semiconductor layer 220, the third semiconductor layer 230, the fourth semiconductor layer 240, the fifth semiconductor layer 250, the sixth semiconductor layer 260, the first transparent conductive layer 310, and the second transparent conductive layer 320, and the perovskite solar cell 500 formed on the substrate-type solar cell.

[0085] Here, the second transparent conductive layer 320 can function as a buffer layer between the substrate-type solar cell and the perovskite solar cell 500, and no separate buffer layer is required.

[0086] The perovskite solar cell 500 may include conductive charge transfer layers 520, 530 and a light absorbing layer 510, similar to that of FIG. 3 described above, and a repeated description thereof will be omitted.

[0087] 5A to 5C are cross-sectional views of a solar cell according to an embodiment of the present invention, which relate to the solar cell according to the above-described FIG. 1. Hereinafter, repeated descriptions of the same components, such as materials, will be omitted.

[0088] First, as can be seen from FIG. 5A, a first semiconductor layer 210 is formed on one surface, for example, the lower surface, of a semiconductor substrate 100, a second semiconductor layer 220 is formed on one surface, for example, the lower surface, of the first semiconductor layer 210, a third semiconductor layer 230 is formed on one surface, for example, the lower surface, of the second semiconductor layer 220, and a first transparent conductive layer 310 is formed on one surface, for example, the lower surface, of the third semiconductor layer 230.

[0089] The first semiconductor layer 210 may be formed as an intrinsic semiconductor layer, for example, an intrinsic amorphous silicon layer, or a semiconductor layer doped with a trace amount of p-type dopant, particularly an amorphous silicon layer doped with a trace amount of p-type dopant, through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0090] The second semiconductor layer 220 may be formed as a p-type amorphous silicon layer through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0091] Here, the first semiconductor layer 210 and the second semiconductor layer 220 may be formed in succession in the same processing equipment. Specifically, the first semiconductor layer 210 made of an intrinsic amorphous silicon layer may be formed by chemical vapor deposition (CVD) or atomic layer deposition (ALD) by introducing a Si source material into a chamber, and then the second semiconductor layer 220 made of a p-type amorphous silicon layer may be formed by chemical vapor deposition (CVD) or atomic layer deposition (ALD) by further introducing a p-type dopant material into the Si source material.

[0092] The third semiconductor layer 230 may be formed as a p+ type semiconductor layer containing WO3 through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD), particularly atomic layer deposition.

[0093] The first transparent conductive layer 310 may be formed of WO3 doped with indium through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0094] Here, the third semiconductor layer 230 and the first transparent conductive layer 310 may be formed in succession in the same process equipment. For example, the third semiconductor layer 230 containing WO3 may be formed by introducing a W-containing material and an O-containing material into a chamber and using chemical vapor deposition (CVD) or atomic layer deposition (ALD) to form the third semiconductor layer 230 containing WO3, and then, the first transparent conductive layer 310 made of indium-doped WO3 may be formed by introducing an indium-containing material into the W-containing material and the O-containing material and using chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0095] Next, as can be seen from FIG. 5B, a fourth semiconductor layer 240 is formed on the other side, e.g., the upper surface, of the semiconductor substrate 100, a fifth semiconductor layer 240 is formed on the other side, e.g., the upper surface, of the fourth semiconductor layer 240, and a second transparent conductive layer 320 is formed on the other side, e.g., the upper surface, of the fifth semiconductor layer 250.

[0096] The fourth semiconductor layer 240 may be formed as an intrinsic semiconductor layer, for example, an intrinsic amorphous silicon layer, or a semiconductor layer doped with a trace amount of n-type dopant, particularly an amorphous silicon layer doped with a trace amount of n-type dopant, through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0097] According to an embodiment of the present invention, the fifth semiconductor layer 250 may be formed as an n-type amorphous silicon layer through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0098] Here, the fourth semiconductor layer 240 and the fifth semiconductor layer 250 may be formed in succession in the same processing equipment. Specifically, the fourth semiconductor layer 240 may be formed as an intrinsic amorphous silicon layer by chemical vapor deposition (CVD) or atomic layer deposition (ALD) by introducing a Si source material into a chamber, and then the fifth semiconductor layer 250 may be formed as an n-type amorphous silicon layer by chemical vapor deposition (CVD) or atomic layer deposition (ALD) by further introducing an n-type dopant material into the Si source material.

[0099] According to another embodiment of the present invention, the fifth semiconductor layer 250 may be formed of SnO using atomic layer deposition (ALD).

[0100] The second transparent conductive layer 320 may be formed of a transparent oxide film containing indium using chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0101] Here, the fifth semiconductor layer 250 and the second transparent conductive layer 320 may be formed in succession in the same process equipment. For example, a material containing Sn and a material containing O may be introduced into a chamber and the fifth semiconductor layer 250 made of SnO may be formed using chemical vapor deposition (CVD) or atomic layer deposition (ALD). Then, a material containing indium may be further introduced into the Sn and O materials and the second transparent conductive layer 320 made of a transparent oxide film containing indium may be formed using chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0102] In some cases, a material containing Sn and a material containing O may be introduced into the chamber and a SnO layer may be formed using chemical vapor deposition (CVD) or atomic layer deposition (ALD), and then indium may be further doped therein to form the fifth semiconductor layer 250 made of a SnO layer not doped with indium and the second transparent conductive layer 320 made of a transparent oxide film doped with indium and containing the indium.

[0103] 5A and 5B are not necessarily performed in a particular order, that is, the step shown in FIG. 5B may be performed first, followed by the step shown in FIG.

[0104] Next, as shown in FIG. 5C, a first electrode 410 is formed on one surface, for example, the lower surface, of the first transparent conductive layer 310, and a second electrode 420 is formed on the other surface, for example, the upper surface, of the second transparent conductive layer 320.

[0105] There is no particular order between the process of forming the first electrode 410 and the process of forming the second electrode 420 .

[0106] The first electrode 410 and the second electrode 420 may be formed through various patterning processes known in the art, such as screen printing.

[0107] 6A to 6C are cross-sectional views of a solar cell according to another embodiment of the present invention, which relate to the solar cell according to the above-described FIG. 2. Hereinafter, repeated descriptions of the same components, such as materials, will be omitted.

[0108] First, as can be seen from FIG. 6A, a first semiconductor layer 210 is formed on one surface, for example, the lower surface, of the semiconductor substrate 100, a second semiconductor layer 220 is formed on one surface, for example, the lower surface, of the first semiconductor layer 210, a third semiconductor layer 230 is formed on one surface, for example, the lower surface, of the second semiconductor layer 220, and a first transparent conductive layer 310 is formed on one surface, for example, the lower surface, of the third semiconductor layer 230.

[0109] The first semiconductor layer 210 may be formed as an intrinsic semiconductor layer, for example, an intrinsic amorphous silicon layer, or a semiconductor layer doped with a trace amount of p-type dopant, particularly an amorphous silicon layer doped with a trace amount of p-type dopant, through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0110] The second semiconductor layer 220 may be formed as a p-type amorphous silicon layer through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0111] Here, the first semiconductor layer 210 and the second semiconductor layer 220 may be formed in succession in the same processing equipment. Specifically, the first semiconductor layer 210 made of an intrinsic amorphous silicon layer may be formed by chemical vapor deposition (CVD) or atomic layer deposition (ALD) by introducing a Si source material into a chamber, and then the second semiconductor layer 220 made of a p-type amorphous silicon layer may be formed by chemical vapor deposition (CVD) or atomic layer deposition (ALD) by further introducing a p-type dopant material into the Si source material.

[0112] The third semiconductor layer 230 may be formed as a p+ type semiconductor layer containing WO3 through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD), particularly atomic layer deposition.

[0113] The first transparent conductive layer 310 may be formed of WO3 doped with indium through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0114] Here, the third semiconductor layer 230 and the first transparent conductive layer 310 may be formed in succession in the same process equipment. For example, a W-containing material and an O-containing material may be introduced into a chamber to form the third semiconductor layer 230 containing WO3 using chemical vapor deposition (CVD) or atomic layer deposition (ALD), and then an indium-containing material may be introduced into the W-containing material and the O-containing material to form the first transparent conductive layer 310 made of indium-doped WO3 using chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0115] Next, as can be seen from FIG. 6B, a fourth semiconductor layer 240 is formed on the other side, e.g., the upper surface, of the semiconductor substrate 100, a sixth semiconductor layer 260 is formed on the other side, e.g., the upper surface, of the fourth semiconductor layer 240, a fifth semiconductor layer 250 is formed on the other side, e.g., the upper surface, of the sixth semiconductor layer 260, and a second transparent conductive layer 320 is formed on the other side, e.g., the upper surface, of the fifth semiconductor layer 250.

[0116] The fourth semiconductor layer 240 may be formed as an intrinsic semiconductor layer, for example, an intrinsic amorphous silicon layer, or a semiconductor layer doped with a trace amount of n-type dopant, particularly an amorphous silicon layer doped with a trace amount of n-type dopant, through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0117] The sixth semiconductor layer 260 may be formed of an n-type amorphous silicon layer through a thin film deposition process such as chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0118] Here, the fourth semiconductor layer 240 and the sixth semiconductor layer 260 may be formed in succession in the same processing equipment. Specifically, the fourth semiconductor layer 240 may be formed as an intrinsic amorphous silicon layer by chemical vapor deposition (CVD) or atomic layer deposition (ALD) by introducing a Si source material into a chamber, and then the sixth semiconductor layer 260 may be formed as an n-type amorphous silicon layer by chemical vapor deposition (CVD) or atomic layer deposition (ALD) by further introducing an n-type dopant material into the Si source material.

[0119] The fifth semiconductor layer 250 may be formed of SnO using atomic layer deposition (ALD), and the second transparent conductive layer 320 may be formed of a transparent oxide film containing indium using chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0120] Here, the fifth semiconductor layer 250 and the second transparent conductive layer 320 may be formed in succession in the same process equipment. For example, a material containing Sn and a material containing O may be introduced into a chamber and the fifth semiconductor layer 250 made of SnO may be formed using chemical vapor deposition (CVD) or atomic layer deposition (ALD). Then, a material containing indium may be further introduced into the Sn and O materials and the second transparent conductive layer 320 made of a transparent oxide film containing indium may be formed using chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0121] In some cases, a material containing Sn and a material containing O may be introduced into the chamber and a SnO layer may be formed using chemical vapor deposition (CVD) or atomic layer deposition (ALD), and then the SnO layer may be further doped with indium to form the fifth semiconductor layer 250 made of a SnO layer that is not doped with indium, and the second transparent conductive layer 320 made of a transparent oxide film that is doped with indium and contains indium.

[0122] 6A and 6B are not necessarily performed in a particular order, that is, the step shown in FIG. 6B may be performed first, followed by the step shown in FIG.

[0123] Next, as shown in FIG. 6C, a first electrode 410 is formed on one surface, for example, the lower surface, of the first transparent conductive layer 310, and a second electrode 420 is formed on the other surface, for example, the upper surface, of the second transparent conductive layer 320.

[0124] There is no particular order between the process of forming the first electrode 410 and the process of forming the second electrode 420 .

[0125] The first electrode 410 and the second electrode 420 may be formed through various patterning processes known in the art, such as screen printing.

[0126] 7A to 7D are cross-sectional views showing the steps of manufacturing a solar cell according to still another embodiment of the present invention, which relate to the steps of manufacturing the solar cell according to FIG. 3 described above.

[0127] First, as can be seen from FIG. 7A, a first semiconductor layer 210 is formed on one surface, for example, the lower surface, of the semiconductor substrate 100, a second semiconductor layer 220 is formed on one surface, for example, the lower surface, of the first semiconductor layer 210, a third semiconductor layer 230 is formed on one surface, for example, the lower surface, of the second semiconductor layer 220, and a first transparent conductive layer 310 is formed on one surface, for example, the lower surface, of the third semiconductor layer 230.

[0128] The process of FIG. 7A is similar to the process of FIG. 5A described above, so a repeated description will be omitted.

[0129] Next, as can be seen from FIG. 7B, a fourth semiconductor layer 240 is formed on the other side, e.g., the upper surface, of the semiconductor substrate 100, a fifth semiconductor layer 250 is formed on the other side, e.g., the upper surface, of the fourth semiconductor layer 240, and a second transparent conductive layer 320 is formed on the other side, e.g., the upper surface, of the fifth semiconductor layer 250.

[0130] The process of FIG. 7B is similar to the process of FIG. 5B described above, so a repeated description will be omitted.

[0131] 7A and 7B are not necessarily performed in a particular order, that is, the step shown in FIG. 7B may be performed first, followed by the step shown in FIG.

[0132] Next, as can be seen from FIG. 7C, a perovskite solar cell 500 is formed on the other surface, for example the upper surface, of the second transparent conductive layer 320.

[0133] The process of forming the perovskite solar cell 500 may include forming a first conductive charge transfer layer 520 on the upper surface of the second transparent conductive layer 320, forming a light absorbing layer 510 on the upper surface of the first conductive charge transfer layer 520, and forming a second conductive charge transfer layer 530 on the upper surface of the light absorbing layer 510.

[0134] The process of forming the first conductive charge transfer layer 520 may include a process of forming a hole transport layer (HTL) made of an organic material through a thin film deposition process such as evaporation, and the process of forming the second conductive charge transfer layer 530 may include a process of forming an electron transport layer (ETL) made of an organic material through a thin film deposition process such as evaporation.

[0135] The light absorbing layer 510 may be formed by forming a perovskite compound through a solution process or a thin film deposition process such as chemical vapor deposition (CVD).

[0136] Next, as can be seen from FIG. 7D, a second electrode 420 is formed on the other surface, for example the upper surface, of the perovskite solar cell 500, and a first electrode 410 is formed on one surface, for example the lower surface, of the first transparent conductive layer 310.

[0137] There is no particular order between the process of forming the first electrode 410 and the process of forming the second electrode 420. The first electrode 410 and the second electrode 420 may be formed through various pattern forming processes known in the art, such as screen printing.

[0138] 8A to 8D are cross-sectional views showing the steps of manufacturing a solar cell according to still another embodiment of the present invention, which relate to the steps of manufacturing the solar cell according to FIG. 4 described above.

[0139] First, as can be seen from FIG. 8A, a first semiconductor layer 210 is formed on one surface, for example, the lower surface, of a semiconductor substrate 100, a second semiconductor layer 220 is formed on one surface, for example, the lower surface, of the first semiconductor layer 210, a third semiconductor layer 230 is formed on one surface, for example, the lower surface, of the second semiconductor layer 220, and a first transparent conductive layer 310 is formed on one surface, for example, the lower surface, of the third semiconductor layer 230.

[0140] The process of FIG. 8A is similar to the process of FIG. 6A described above, so a repeated description will be omitted.

[0141] Next, as can be seen from FIG. 8B, a fourth semiconductor layer 240 is formed on the other side, e.g., the upper surface, of the semiconductor substrate 100, a sixth semiconductor layer 260 is formed on the other side, e.g., the upper surface, of the fourth semiconductor layer 240, a fifth semiconductor layer 250 is formed on the other side, e.g., the upper surface, of the sixth semiconductor layer 260, and a second transparent conductive layer 320 is formed on the other side, e.g., the upper surface, of the fifth semiconductor layer 250.

[0142] The process of FIG. 8B is similar to the process of FIG. 6B described above, so a repeated description will be omitted.

[0143] On the other hand, there is no particular order between the steps of Figure 8A and Figure 8B, that is, it is also possible to perform the step of Figure 8B first and then the step of Figure 8A.

[0144] Next, as can be seen from FIG. 8C, a perovskite solar cell 500 is formed on the other surface, for example the upper surface, of the second transparent conductive layer 320.

[0145] The process of forming the perovskite solar cell 500 may include forming a first conductive charge transfer layer 520 on the upper surface of the second transparent conductive layer 320, forming a light absorbing layer 510 on the upper surface of the first conductive charge transfer layer 520, and forming a second conductive charge transfer layer 530 on the upper surface of the light absorbing layer 510.

[0146] The process of forming the first conductive charge transfer layer 520 may include a process of forming a hole transport layer (HTL) made of an organic material through a thin film deposition process such as evaporation, and the process of forming the second conductive charge transfer layer 530 may include a process of forming an electron transport layer (ETL) made of an organic material through a thin film deposition process such as evaporation.

[0147] The light absorbing layer 510 may be formed by forming a perovskite compound through a solution process or a thin film deposition process such as chemical vapor deposition (CVD).

[0148] Next, as can be seen from FIG. 8D, a second electrode 420 is formed on the other surface, for example the upper surface, of the perovskite solar cell 500, and a first electrode 410 is formed on one surface, for example the lower surface, of the first transparent conductive layer 310.

[0149] There is no particular order between the process of forming the first electrode 410 and the process of forming the second electrode 420. The first electrode 410 and the second electrode 420 may be formed through various pattern forming processes known in the art, such as screen printing.

[0150] Although the present invention has been described in detail above with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments and can be embodied in various modifications without departing from the spirit and scope of the present invention. Therefore, the disclosed embodiments are intended to illustrate, rather than limit, the spirit and scope of the present invention, and the above-described embodiments should not be construed as limiting the spirit and scope of the present invention. Therefore, the above-described embodiments should be understood to be illustrative in all respects and not restrictive. The scope of the present invention should be interpreted by the scope of the claims, and all technical concepts within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

Claims

1. semiconductor substrate, a first semiconductor layer provided on one surface of the semiconductor substrate; a second semiconductor layer provided on one surface of the first semiconductor layer; a third semiconductor layer provided on one surface of the second semiconductor layer; a first transparent conductive layer provided on one surface of the third semiconductor layer; a first electrode provided on one surface of the first transparent conductive layer; a fourth semiconductor layer provided on the other surface of the semiconductor substrate; a fifth semiconductor layer provided on the other surface of the fourth semiconductor layer; a second transparent conductive layer provided on the other surface of the fifth semiconductor layer; and a second electrode provided on the other surface of the second transparent conductive layer; the second semiconductor layer comprises a p-type semiconductor material, and the third semiconductor layer comprises a p-type semiconductor material including tungsten oxide (WO 3 ); the fifth semiconductor layer comprises an n-type semiconductor material containing tin (Sn), the fourth semiconductor layer is made of an intrinsic amorphous silicon layer, an n-type amorphous silicon layer is further provided between the fourth semiconductor layer and the fifth semiconductor layer, A solar cell, wherein the band gap of the fifth semiconductor layer is larger than the band gap of the n-type amorphous silicon layer, and the conduction band minimum energy level of the fifth semiconductor layer is higher than the conduction band minimum energy level of the n-type amorphous silicon layer.

2. 2. The solar cell of claim 1, wherein the band gap of the third semiconductor layer is smaller than the band gap of the second semiconductor layer, and the valence band maximum energy level of the third semiconductor layer is lower than the valence band maximum energy level of the second semiconductor layer.

3. The solar cell according to claim 1 , wherein the first transparent conductive layer is made of a transparent oxide film containing indium.

4. The solar cell according to claim 1 , wherein the first semiconductor layer is an intrinsic amorphous silicon layer.

5. 2. The solar cell according to claim 1, wherein the fifth semiconductor layer has a thickness in the range of 10 Å to 100 Å, and the second transparent conductive layer has a thickness in the range of 100 Å to 500 Å.

6. 2. The solar cell according to claim 1, wherein the second transparent conductive layer is made of a transparent oxide film containing indium, and the concentration of indium in the transparent oxide film is in the range of 1 atomic % to 5 atomic %.

7. 7. The solar cell according to claim 6, wherein the first transparent conductive layer is made of a transparent oxide film containing indium, and the content of indium contained in the first transparent conductive layer is greater than the content of indium contained in the second transparent conductive layer.

8. The solar cell further includes a perovskite solar cell disposed between the second transparent conductive layer and the second electrode, The perovskite solar cell comprises: a first conductive charge transport layer comprising a hole transport layer in contact with the second transparent conductive layer; a light absorbing layer formed of a perovskite compound on the first conductive charge transport layer; and 10. The solar cell of claim 1, further comprising a second conductive charge transfer layer comprising an electron transport layer disposed on said light absorbing layer.

9. forming a first semiconductor layer on one surface of a semiconductor substrate; forming a second semiconductor layer on one surface of the first semiconductor layer; forming a third semiconductor layer on one surface of the second semiconductor layer; forming a first transparent conductive layer on one surface of the third semiconductor layer; forming a first electrode on the first transparent conductive layer; forming a fourth semiconductor layer on the other surface of the semiconductor substrate; forming a fifth semiconductor layer on the other surface of the fourth semiconductor layer; forming a second transparent conductive layer on the other surface of the fifth semiconductor layer; and forming a second electrode on the other surface of the second transparent conductive layer; forming the third semiconductor layer includes forming a p-type semiconductor material including tungsten oxide (WO3); the step of forming the third semiconductor layer and the step of forming the first transparent conductive layer are continuous steps carried out in the same processing equipment, the step of forming the fifth semiconductor layer includes the step of forming an n-type semiconductor material including tin (Sn), A method for manufacturing a solar cell, wherein the step of forming the fifth semiconductor layer and the step of forming the second transparent conductive layer are successive steps carried out in the same processing equipment.

10. The method for manufacturing a solar cell according to claim 9 , wherein the step of forming the first transparent conductive layer comprises the step of forming a transparent oxide film containing indium.

11. the step of forming the fifth semiconductor layer includes a step of forming SnO by introducing a material containing Sn and a material containing O into a chamber, 10. The method for manufacturing a solar cell according to claim 9, wherein the forming step of the second transparent conductive layer comprises a step of forming a transparent oxide film containing indium by putting the material containing Sn, the material containing O, and a material containing indium into the chamber.

12. 10. The method for manufacturing a solar cell according to claim 9, wherein the forming step of the fifth semiconductor layer and the forming step of the second transparent conductive layer comprise the steps of: charging a material containing Sn and a material containing O into a chamber to form a SnO layer; and then further doping the SnO layer with indium, thereby forming the fifth semiconductor layer made of a SnO layer that is not doped with indium, and the second transparent conductive layer made of a transparent oxide film doped with indium and containing the indium.

13. further comprising a step of forming an n-type amorphous silicon layer between the step of forming the fourth semiconductor layer and the step of forming the fifth semiconductor layer; 10. The method for manufacturing a solar cell according to claim 9, wherein the step of forming the fourth semiconductor layer and the step of forming the n-type amorphous silicon layer are continuous steps carried out in the same processing equipment.

14. forming a perovskite solar cell between the second transparent conductive layer and the second electrode; forming the perovskite solar cell, forming a first conductive charge transfer layer comprising a hole transport layer in contact with the second transparent conductive layer; forming a light absorbing layer made of a perovskite compound on the first conductive charge transport layer; and 10. The method for producing a solar cell according to claim 9, further comprising the step of forming a second conductive charge transfer layer made of an electron transport layer on the light absorbing layer.

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