TW201442258A - Solar cell and manufacturing method thereof - Google Patents

Abstract

A solar cell and a manufacturing method thereof are provided, wherein the manufacturing method includes following steps. A photoelectric conversion layer is provided. A transparent conductive layer is respectively formed on a first surface and an opposite second surface of the photoelectric conversion layer. A cover layer is formed on each of the transparent conductive layers. A seed layer is formed on each of the insulating layers. An electrode layer is formed on each of the seed layers, wherein a thickness of each of the insulating layers is within 50 to 850 angstrom, such that each of the electrode layers is capable of electrically connected to the corresponding transparent conductive layer through the seed layer diffusing into the insulating layer.

Description

Solar cell and method of manufacturing same

The present invention relates to a photoelectric conversion element and a method of fabricating the same, and more particularly to a solar cell and a method of fabricating the same.

With the shortage of petrochemical energy and increasing energy demand, the development of renewable energy (Renewable energy) has become one of the most important issues today. Renewable energy refers to sustainable and non-polluting natural energy sources such as solar energy, wind energy, hydropower, tidal energy or biomass energy. Among them, the use of solar energy is very important in the research of energy development in recent years. A popular part.

A solar cell is an energy-converting photovoltaic device that converts the energy of light into electrical energy through the illumination of sunlight. 1 is a schematic cross-sectional view of a conventional solar cell. Referring to FIG. 1, a solar cell 100 includes a photoelectric conversion layer 110, transparent conductive layers 120a and 120b, and electrode layers 130a and 130b. The electrode layers 130a and 130b are respectively disposed on the first surface S1 and the second surface S2 of the photoelectric conversion layer 110, wherein the first surface S1 is opposite to the second surface S2, and the transparent conductive layer 120a is disposed on the photoelectric conversion layer 110 and the electrode layer. Between 130a, and through The conductive layer 120b is disposed between the photoelectric conversion layer 110 and the electrode layer 130b.

In general, the electrode layer 130a disposed on the light-receiving surface (referred to as the first surface S1) of the photoelectric conversion layer 110 is required to effectively collect the carrier, and the ratio of the incident light to the electrode layer 130a is also minimized. Therefore, the electrode layer 130a on the light receiving surface is generally designed to have a special pattern structure, for example, a plurality of very fine finger electrodes extending from a bus bar. It is conventional to form the electrode pattern (refer to the bus electrode and the finger electrode), and silver paste (not shown) is usually applied to the transparent conductive layer 120a by screen printing. In addition, a co-sintering process is required to cure the silver paste into the electrode layer 130a. However, the co-sintering process is a high-temperature process (over 700 degrees Celsius), which easily damages the film layer in the solar cell 100, particularly the amorphous germanium semiconductor layer in a Hetero-junction-based solar cell. In addition, the width of the finger electrode or the bus electrode in the electrode layer 130a is also limited by the high temperature process, and cannot be further reduced, thereby limiting the photoelectric conversion efficiency of the solar cell. On the other hand, if the temperature of the co-sintering process is lowered, the quality of the electrode layer 130a is affected. Therefore, how to improve the reliability of the solar cell (that is, how to reduce the damage of the electrode layer process to the film layer in the solar cell), and further improve the photoelectric conversion efficiency of the solar cell, is a future trend.

The present invention provides a method for producing a solar cell, which can produce a solar cell having high reliability and excellent photoelectric conversion efficiency.

The invention provides a solar cell with high reliability and good performance Photoelectric conversion efficiency.

A method of manufacturing a solar cell of the present invention comprises the following steps. A photoelectric conversion layer is provided. A transparent conductive layer is formed on each of the first surface and the second surface opposite to the photoelectric conversion layer. A cover layer is formed on each of the transparent conductive layers. A seed layer is formed on each of the cover layers. Forming an electrode layer on each of the sub-layers, wherein each of the cover layers has a thickness of between 50 and 850 angstroms, such that the electrode layers are electrically connected to the corresponding transparent conductive layer through the seed layer diffused into the cover layer, respectively. .

In an embodiment of the invention, the photoelectric conversion layer is a PN junction structure formed by stacking a P-type semiconductor layer and an N-type semiconductor layer, or is formed by stacking a P-type semiconductor layer, an intrinsic layer, and an N-type semiconductor layer. PIN junction structure.

In an embodiment of the invention, the material of the transparent conductive layer comprises a metal oxide.

In an embodiment of the invention, the material of the cover layer comprises yttrium oxide, tantalum nitride, yttrium oxynitride, lanthanum aluminum oxide or a stacked layer of at least two materials.

In an embodiment of the invention, the material of the seed layer comprises silver, and the method of forming the seed layer comprises spraying, injecting or screen printing.

In an embodiment of the invention, the various sub-layers are laminated structures, and the material of the seed layer further comprises nickel, copper, aluminum, cobalt, titanium, or a mixture of at least two of the foregoing, a metal telluride (such as bismuth Nickel, cobalt telluride, titanium telluride, etc.) or a stacked layer of at least two of the above materials, and the method of forming the seed layer further comprises electroless plating (electroless), electroplating, physical vapor deposition (PVD) or chemical vapor deposition (CVD).

In an embodiment of the invention, the electrode layer includes a first electrode layer and a second electrode layer. The first electrode layer covers the seed layer, and the second electrode layer covers the first electrode layer. The material of the first electrode layer comprises a conductive metal (such as silver, nickel, copper, aluminum, titanium, cobalt or a mixture of at least two of the above) and a metal halide (such as nickel telluride, cobalt telluride or titanium telluride), and the second electrode The material of the layer includes tin, silver or nickel.

A solar cell of the present invention comprises a photoelectric conversion layer, a transparent conductive layer, a cover layer, a seed layer, an electrode layer, another transparent conductive layer, another cover layer, another seed layer, and another electrode layer. The transparent conductive layer is disposed on the first surface of the photoelectric conversion layer. The cover layer is disposed on the transparent conductive layer, wherein the cover layer has a thickness of between 50 and 850 angstroms. The seed layer is disposed on the transparent conductive layer, and the seed layer is electrically connected to the transparent conductive layer. The electrode layer is disposed on the seed layer. Another transparent conductive layer is disposed on the second surface of the photoelectric conversion layer, wherein the first surface and the second surface are opposite to each other. Another cover layer is disposed on the other transparent conductive layer, wherein the other cover layer has a thickness of between 50 and 850 angstroms. Another seed layer is disposed on another transparent conductive layer and electrically connected to another transparent conductive layer. The other electrode layer is disposed on another seed layer.

In an embodiment of the invention, the photoelectric conversion layer is a PN junction structure formed by stacking a P-type semiconductor layer and an N-type semiconductor layer, or is formed by stacking a P-type semiconductor layer, an intrinsic layer, and an N-type semiconductor layer. PIN junction structure.

In an embodiment of the invention, the transparent conductive layer and another transparent The material of the conductive layer includes a metal oxide.

In an embodiment of the invention, the material of the cover layer and the other cover layer comprises iridium oxide, tantalum nitride, yttrium oxynitride, lanthanum aluminum oxide or a stacked layer of at least two materials.

In an embodiment of the invention, the seed layer and the material of the other seed layer comprise silver.

In an embodiment of the invention, the seed layer and the other seed layer are respectively laminated structure, and the material of the seed layer and the other seed layer further comprises a conductive metal other than silver (such as nickel, copper, aluminum, cobalt). , titanium or a mixture of at least two of the foregoing) and a metal halide (such as nickel telluride, cobalt telluride, titanium telluride) or a stacked layer of at least two of the foregoing.

In an embodiment of the invention, the electrode layer includes a first electrode layer and a second electrode layer. The first electrode layer covers the seed layer, and the second electrode layer covers the first electrode layer. The material of the first electrode layer comprises silver, nickel, copper, aluminum, cobalt, titanium or a mixture of at least two of the above, a metal halide (such as nickel telluride, cobalt telluride or titanium telluride), and the material of the second electrode layer comprises tin , silver or nickel.

Based on the above, the present invention forms a cover layer and a seed layer on the transparent conductive layer, whereby the material of the electrode layer is selectively grown on the seed layer. Thus, the present invention can modulate the electrode pattern (the junction electrode of the electrode layer and the finger electrode) through the pattern design of the seed layer, and the electrode pattern can be formed without the screen printing and the co-sintering process. Therefore, damage to the solar cell due to the co-sintering process can be avoided, and the solar cell can be highly reliable. Furthermore, the invention can be made by seed The layer is arranged to increase the adhesion of the electrode layer and the transparent conductive layer, and reduce the contact resistance between the electrode layer and the transparent conductive layer, thereby enabling the solar cell to have good photoelectric conversion efficiency.

The above described features and advantages of the invention will be apparent from the following description.

100, 200‧‧‧ solar cells

110, 210‧‧‧ photoelectric conversion layer

120a, 120b, 220A, 220B‧‧‧ transparent conductive layer

130a, 130b, 250A, 250B‧‧‧ electrode layers

212‧‧‧矽 substrate

214A, 214B‧‧‧ Passivation layer

216A‧‧‧first type semiconductor layer

216B‧‧‧Second type semiconductor layer

230A, 230B‧‧ ‧ overlay

240A, 240B‧‧‧ seed layer

242, 246‧‧‧ first seed layer

244, 248‧‧‧ second seed layer

252, 256‧‧‧ first electrode layer

254, 258‧‧‧ second electrode layer

A1, A2‧‧‧ area

S1‧‧‧ first surface

S2‧‧‧ second surface

T‧‧‧ thickness

1 is a schematic cross-sectional view of a conventional solar cell.

2A-2F are schematic cross-sectional views showing a manufacturing process of a solar cell according to an embodiment of the invention.

2A-2F are schematic cross-sectional views showing a manufacturing process of a solar cell according to an embodiment of the invention. Referring to FIG. 2A, a photoelectric conversion layer 210 is provided, wherein the photoelectric conversion layer 210 has opposite first and second surfaces S1 and S2. The first surface S1 is, for example, a light receiving surface, that is, a surface facing external light (not shown, for example, sunlight) to absorb photons, and the second surface S2 is, for example, a non-light receiving surface, that is, a surface facing away from external light. .

The photoelectric conversion layer 210 may be a PN junction structure formed by stacking a P-type semiconductor layer and an N-type semiconductor layer, or a PIN junction structure formed by stacking a P-type semiconductor layer, an intrinsic layer, and an N-type semiconductor layer.

For example, the photoelectric conversion layer 210 includes, for example, a germanium substrate 212, a passivation layer 214A, 214B, a first type semiconductor layer 216A, and a second type semiconductor layer 216B, wherein the first type semiconductor layer 216A and the second type semiconductor layer 216B The insulating layer 214A is located between the first type semiconductor layer 216A and the germanium substrate 212, and the passivation layer 214B is located between the second type semiconductor layer 216B and the germanium substrate 212. In the present embodiment, the first type semiconductor layer 216A has a contact surface with the passivation layer 214A, and the surface of the first type semiconductor layer 216A with respect to the contact surface is the first surface S1 of the photoelectric conversion layer 210. On the other hand, the second type semiconductor layer 216B and the passivation layer 214B also have a contact surface, and the surface of the second type semiconductor layer 216B with respect to the contact surface is the second surface S2 of the photoelectric conversion layer 210.

In the present embodiment, the crucible substrate 212 is, for example, a P-type tantalum substrate or an N-type tantalum substrate. The passivation layers 214A, 214B, the first type semiconductor layer 216A, and the second type semiconductor layer 216B are, for example, amorphous germanium semiconductor layers, and are formed, for example, by plasma gain chemical vapor deposition. One of the first type semiconductor layer 216A and the second type semiconductor layer 216B is an N type semiconductor layer, and the other of the first type semiconductor layer 216A and the second type semiconductor layer 216B is a P type semiconductor layer.

It should be noted that although the photoelectric conversion layer of a silicon-based solar cell is exemplified in the present embodiment, the type of the photoelectric conversion layer depends on the type of the solar cell, and thus the present invention does not limit the photoelectricity. The type of conversion layer.

In addition, in order to improve the ability to absorb photons and reduce the reflection of external light, the embodiment may also selectively surface-weave the light-receiving surface of the ruthenium substrate 212 (for example, the surface of the ruthenium substrate 212 and the passivation layer 214A). Forming a weaving table surface. The surface weaving process is, for example, but not limited to, carried out using a potassium hydroxide (KOH) solution.

Referring to FIG. 2B, a transparent conductive layer 220A is formed on the first surface S1 of the photoelectric conversion layer 210, and another transparent conductive layer 220B is formed on the second surface S2 of the photoelectric conversion layer 210. Here, the transparent conductive layers 220A, 220B can serve as a window layer, which can be used to modulate photoelectric conversion efficiency, light transmittance, carrier collection efficiency, and the like. In this embodiment, the material of the transparent transparent conductive layers 220A, 220B is, for example, a metal oxide such as indium tin oxide, indium zinc oxide, aluminum tin oxide, aluminum zinc oxide, indium antimony zinc oxide, or the like. A suitable oxide, or a stacked layer of at least two of the foregoing. Further, a method of forming the transparent transparent conductive layers 220A, 220B is, for example, an evaporation method, a sputtering method, or other methods suitable for depositing a metal oxide.

Referring to FIG. 2C, a cap layer 230A is formed on the transparent conductive layer 220A. In the present embodiment, the material of the cap layer 230A is, for example, tantalum oxide, tantalum nitride, hafnium oxynitride, hafnium aluminum oxide or a stacked layer of at least two of the above materials, and the cap layer 230A is deposited, for example, by physical vapor deposition ( Physical Vapor Deposition (PVD), Chemical Vapor Deposition (CVD) or electroplating is performed at low temperatures (temperature range between 150 and 250 degrees Celsius) to avoid forming in solar cells. The other layers cause damage.

In detail, the thickness T of the cover layer 230A of the present embodiment is between 50 and 850 angstroms, and the refractive index is, for example, between 1.7 and 3.5 (the above-mentioned "between" includes the endpoint value), and therefore, covering In addition to having low conductivity (ie, high resistance), layer 230A has High penetration and reduced reflection of external light. In addition, the process of the cap layer 230A is compatible with the process of the existing solar cell, and is not required to be removed after formation. Therefore, the cover layer 230A of the present embodiment has the advantages of simple process, in addition to protecting the solar cell (for example, avoiding scratching or dampening of the solar cell, etc.) and reducing reflection of external light.

Referring to FIG. 2D, a seed layer 240A is formed on the cover layer 230A. In this embodiment, the seed layer 240A is suitable for electrically connecting the electrode layer to be formed (shown later) to the transparent conductive layer 220A, and can also be used as a seed crystal for the electrode layer. In other words, in this embodiment, the electrode pattern of the electrode layer (the bus electrode of the electrode layer and the finger electrode) can be modulated by the pattern design of the seed layer 240A. Since the seed layer 240A and the electrode layer to be formed are located on the light receiving surface of the solar cell, the pattern of the seed layer 240A (ie, the electrode layer to be formed) is not completely covered, considering the ratio of the electrode layer to be formed to shield the incident light. On the transparent conductive layer 220A. That is, the seed layer 240A covers the area A1 of the portion of the cover layer 230A and exposes the remaining area A2 of the cover layer 230A.

In the present embodiment, the seed layer 240A is exemplified by a laminated structure. Specifically, the seed layer 240A of the present embodiment includes a first sub-seed layer 242 and a second sub-seed layer 244 , wherein the first sub-seed layer 242 is interposed between the transparent conductive layer 220A and the second sub-seed layer 244 .

When the first sub-seed layer 242 is formed, the material of the first sub-seed layer 242 is adapted to diffuse into the cap layer 230A, that is, the material of the first sub-seed layer 242 needs to have appropriate diffusibility, and thus, Through the material of the first sub-seed layer 242 The design of the thickness T of the cap layer 230A (shown in FIG. 2C) is selected and the cap layer 230A at which the first sub-seed layer 242 is to be formed is not removed (ie, the cap layer 230A of the region A1 is not removed). The first sub-seed layer 242 can also be electrically connected to the transparent conductive layer 220A. In the present embodiment, the material of the first sub-seed layer 242 is, for example, silver, and the method of forming the first sub-seed layer 242 may be spray or screen printing.

The second sub-seed layer 244 is suitable as a seed for the electrode layer to be grown, and therefore, the material end of the second sub-seed layer 244 depends on the material of the electrode layer. For example, when copper is selected as the material of the electrode layer, the material of the second sub-seed layer 244 may be selected from materials matching copper. In other embodiments, the material of the second sub-seed layer 244 may also be nickel, copper, aluminum, cobalt, titanium or a mixture of at least two of the above, a metal telluride (such as nickel antimonide, cobalt telluride, titanium antimonide) or the above The stacked layers of at least two materials, and the method of forming the seed layer may be a method such as electroless plating, electroplating, physical vapor deposition, or chemical vapor deposition. In this embodiment, if nickel, copper, aluminum, cobalt, titanium or a mixture of at least two, a metal halide (such as nickel telluride, cobalt telluride, titanium telluride) or a stacked layer of at least two materials is used, Replacing the use of silver or reducing the amount of silver used can further reduce process costs.

It should be noted that, although the laminated structure is exemplified in the embodiment, in other embodiments not shown, the seed layer may have a single layer structure. For example, when silver is selected as the material of the electrode layer, the material of the seed layer may be selected from silver as a material of the diffusion layer and the seed crystal. Therefore, after forming a single layer seed layer on the cover layer 230A, the electrode layer can be directly fabricated.

Referring to FIG. 2E, an electrode layer 250A is formed on the seed layer 240A. electrode The layer 250A is located on the light receiving surface of the solar cell and is adapted to collect the carriers emitted from the photoelectric conversion layer 210. Further, the electrode layer 250A may be a single layer or a laminated structure. In the present embodiment, the electrode layer 250A is exemplified by a laminated structure.

In detail, the electrode layer 250A of the present embodiment includes a first electrode layer 252 and a second electrode layer 254, wherein the first electrode layer 252 covers the seed layer 240A, and the second electrode layer 254 covers the first electrode layer 252. on. In addition to avoiding oxidation of the first electrode layer 252, the second electrode layer 254 can also serve as an inter-layer for assembly of subsequent solar cell modules, thereby improving adhesion.

In this embodiment, the material of the first electrode layer 252 may be silver, nickel, copper, aluminum, cobalt, titanium or a mixture of at least two of the above, a metal halide (such as nickel telluride, cobalt telluride or titanium telluride). The material of the second conductivity layer 254 may be a material that is less susceptible to oxidation, such as tin, silver or nickel. Further, the method of forming the first electrode layer 252 and the second electrode layer 254 may be a method such as electroless plating or electroplating. Since the conductivity of copper is higher than the conductivity of silver, if copper is used as the material of the first electrode layer 252, in addition to reducing the process cost, the photoelectric conversion efficiency and the filling factor of the solar cell can be further improved. Factor).

In the present embodiment, the cap layer 230A and the seed layer 240A have different electroless plating rates or plating rates, and before the electrode layer 250A is formed, the cap layer 230A and the seed layer 240A are formed on the transparent conductive layer 220A. Therefore, in the process of forming the electrode layer 250A, the material of the electrode layer 250A is selectively grown on the seed layer 240A. In this way, the embodiment can modulate the electrode pattern of the electrode layer 250A through the pattern design of the seed layer 240A (the junction electrode and the finger electrode of the electrode layer) The electrode pattern can be formed without using a screen printing and co-sintering process. Therefore, the present embodiment can avoid damage to the solar cell due to the co-sintering process (high-temperature process), thereby making the solar cell highly reliable. In addition, in this embodiment, the adhesion of the electrode layer 250A and the transparent conductive layer 220A can be increased by the setting of the seed layer 240A, and the contact resistance between the electrode layer 250A and the transparent conductive layer 220A can be reduced, thereby making the solar cell have good performance. Photoelectric conversion efficiency.

Referring to FIG. 2F, another cap layer 230B, another seed layer 240B (including the first sub-seed layer 246 and the second sub-seed layer 248), and another electrode layer 250B are formed on the second surface S2 of the photoelectric conversion layer 210. (including the first electrode layer 256 and the second electrode layer 258), wherein the method of forming the film layers can be referred to FIG. 2C to FIG. 2E and its corresponding description, and details are not described herein again. Here, the solar cell 200 is initially completed.

It should be noted that since the electrode layer 250B is located on the non-light-receiving surface of the solar cell 200, the electrode layer 250B is not shielded from incident light. In other words, the pattern design of the electrode layer 250B can have greater design flexibility, and the pattern design of the seed layer 240B can also have greater design flexibility. In other embodiments not shown, the pattern design of the seed layer 240B and the electrode layer 250B on the non-light-receiving surface may be different from the pattern design of the seed layer 240A and the electrode layer 250A on the light-receiving surface, or alternatively, the seed layer 240B And the electrode layer 250B may be completely covered on the transparent conductive layer 220B, that is, the seed layer 240B directly contacts the transparent conductive layer 220B without additionally generating the cover layer 230B.

In summary, the present invention forms a cover layer and a seed on a transparent conductive layer. a layer whereby the material of the electrode layer is selectively grown on the seed layer. Thus, the present invention can modulate the electrode pattern of the electrode layer (the junction electrode of the electrode layer and the finger electrode) through the pattern design of the seed layer, and the electrode pattern can be formed without the screen printing and the co-sintering process. Therefore, damage to the solar cell due to the co-sintering process can be avoided, and the solar cell can be highly reliable. In addition, the present invention can increase the adhesion of the electrode layer and the transparent conductive layer by the arrangement of the seed layer, and reduce the contact resistance between the electrode layer and the transparent conductive layer, thereby enabling the solar cell to have good photoelectric conversion efficiency.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some modifications and refinements, for example, without departing from the spirit and scope of the invention. The method for forming the above electrode pattern (including the fabrication of the cover layer and the seed layer) is applied to a thin film solar cell or a III-V solar cell, and the scope of protection of the present invention is defined by the scope of the appended patent application. quasi.

200‧‧‧ solar cells

210‧‧‧ photoelectric conversion layer

212‧‧‧矽 substrate

214A, 214B‧‧‧ Passivation layer

216A‧‧‧first type semiconductor layer

216B‧‧‧Second type semiconductor layer

220A, 220B‧‧‧ transparent conductive layer

230A, 230B‧‧ ‧ overlay

240A, 240B‧‧‧ seed layer

242, 246‧‧‧ first seed layer

244, 248‧‧‧ second seed layer

250A, 250B‧‧‧ electrode layer

252, 256‧‧‧ first electrode layer

254, 258‧‧‧ second electrode layer

S1‧‧‧ first surface

S2‧‧‧ second surface

Claims (14)

A method for manufacturing a solar cell, comprising: providing a photoelectric conversion layer; forming a transparent conductive layer on a first surface and a second surface opposite to the photoelectric conversion layer; forming a coating layer on each of the transparent conductive layers Forming a sub-layer on each of the cover layers; and forming an electrode layer on each of the seed layers, wherein each of the cover layers has a thickness of between 50 and 850 angstroms, so that the electrode layers are respectively diffused and diffused The seed layer in the cover layer is electrically connected to the corresponding transparent conductive layer. The method for manufacturing a solar cell according to claim 1, wherein the photoelectric conversion layer is a PN junction structure formed by stacking a P-type semiconductor layer and an N-type semiconductor layer, or a P-type semiconductor layer, an intrinsic layer, A PIN junction structure formed by stacking N-type semiconductor layers. The method of manufacturing a solar cell according to claim 1, wherein the material of the transparent conductive layer comprises a metal oxide. The method for manufacturing a solar cell according to claim 1, wherein the material of the cover layer comprises ruthenium oxide, tantalum nitride, ruthenium oxynitride, ruthenium aluminum oxide or a stacked layer of at least two materials. The method of manufacturing a solar cell according to claim 1, wherein the material of the seed layer comprises silver, and the method of forming the seed layer comprises spraying, spraying or screen printing. The method for manufacturing a solar cell according to claim 5, wherein each of the seed layers is a laminated structure, and the material of the seed layer further comprises nickel, aluminum, cobalt, titanium, or a mixture of at least two of the foregoing. a nickel-deposited nickel, cobalt telluride, titanium telluride or a stacked layer of at least two of the above materials, and the method of forming the seed layer further comprises electroless plating, electroplating, physical vapor deposition or chemical vapor deposition. The method for manufacturing a solar cell according to claim 1, wherein the electrode layer comprises a first electrode layer and a second electrode layer, the first electrode layer covers the seed layer, and the second electrode a layer covering the first electrode layer, the material of the first electrode layer comprises silver, nickel, copper, aluminum, titanium, cobalt or a mixture of at least two of the above, nickel telluride, cobalt telluride or titanium telluride, and the first The material of the two electrode layers includes tin, silver or nickel. A solar cell comprising: a photoelectric conversion layer; a transparent conductive layer disposed on a first surface of the photoelectric conversion layer; a cover layer disposed on the transparent conductive layer, wherein the cover layer has a thickness of 50 Between 850 angstroms; a sub-layer disposed on the transparent conductive layer and electrically connected to the transparent conductive layer; an electrode layer disposed on the seed layer; and another transparent conductive layer disposed on the photoelectric conversion a second surface of the layer, wherein the first surface and the second surface are opposite to each other; another cover layer disposed on the other transparent conductive layer, wherein the another cover The thickness of the layer is between 50 and 850 angstroms; another seed layer is disposed on the other transparent conductive layer and electrically connected to the other transparent conductive layer; and another electrode layer is disposed on the other On the seed layer. The solar cell according to claim 8, wherein the photoelectric conversion layer is a PN junction structure formed by stacking a P-type semiconductor layer and an N-type semiconductor layer, or a P-type semiconductor layer, an intrinsic layer, an N-type semiconductor The PIN junction structure formed by layer stacking. The solar cell of claim 8, wherein the transparent conductive layer and the material of the other transparent conductive layer comprise a metal oxide. The solar cell of claim 8, wherein the cover layer and the material of the other cover layer comprise ruthenium oxide, tantalum nitride, bismuth oxynitride, lanthanum aluminum oxide or a stacked layer of at least two of the above materials. . The solar cell of claim 8, wherein the seed layer and the material of the other seed layer comprise silver. The solar cell of claim 12, wherein the seed layer and the other seed layer are each a laminated structure, and the seed layer and the material of the other seed layer further comprise nickel, copper, aluminum, Cobalt, titanium or a mixture of at least two of the foregoing, nickel telluride, cobalt telluride, titanium telluride or a stacked layer of at least two of the above materials. The solar cell of claim 8, wherein the electrode layer comprises a first electrode layer and a second electrode layer, the first electrode layer covers the seed layer, and the second electrode layer covers the On an electrode layer, the first electrode layer The material includes silver, nickel, copper, aluminum, cobalt, titanium or a mixture of at least two of the foregoing, nickel telluride, cobalt telluride or titanium telluride, and the material of the second electrode layer comprises tin, silver or nickel.