TWI467782B - Thin film solar cell - Google Patents

Description

Thin film solar cell

The invention relates to a thin film solar cell, in particular to a thin film solar cell comprising a nano metal particle layer, which increases the capture of incident light and the utilization of light by the nano metal particle layer to improve photocurrent and photoelectric conversion efficiency.

The international energy shortage has made the application of solar cells more and more valued by many governments and the public. Because there is no shortage of solar energy supply, and the process of producing electric energy will not cause environmental pollution, it will become a hot alternative energy source and drive the solar cell industry to flourish. . The energy radiated from the surface of the sun is converted into electricity of about 3.8 × 10 ²³ kW; the total amount of solar energy, such as the amount of solar energy received on the earth converted from the sun 150 million kilometers, is about 1.77 in electricity. ×10 ¹⁴ kW or so, this value is about 100,000 times the annual average annual power consumption. If this energy can be used effectively, it will not only solve the problem of consumable energy, but even environmental problems can be solved. Among the many solar cell technologies, thin-film solar cells have attracted attention because of the advantages of using less raw materials, high total power generation, and integration with building materials.

At present, most of the thin film solar cells using glass as a substrate adopt a Superstrate structure. The Superstrate structure is to plate a transparent conductive layer (TCO) on a glass substrate, and then sequentially plate a PIN three-layer ruthenium film layer (also referred to as a light absorbing layer), and finally plate a metal layer, and the incident light passes through the glass substrate. The end enters the solar cell. Since the bottom layer of the thin-film solar cell of the Superstrate structure is metal, if the incident light is not completely absorbed by the light absorbing layer, the light can be reflected back to the absorbing layer by the metal reflective layer, and the light energy can be utilized again. However, due to the poor adhesion of the metal layer to the crucible, if the metal layer is directly deposited on the crucible, the light is absorbed by the defect between the metal layer and the crucible, so that the light cannot be effectively reflected back to the absorption layer, so the metal layer and the crucible are often A TCO layer is added between them to increase the reflectivity of the light and improve the stability of the component.

Therefore, the Superstrate structured thin film solar cell requires two layers of transparent conductive layers, the layer closer to the incident light is called the forward transparent conductive layer (Front TCO), and the other layer is called the back transparent conductive layer (Back TCO). If the surface is flat, the incident light is straight into and out of the thin film solar cell, and solar energy cannot be effectively utilized. If the TCO has an irregular texture, the degree of light scattering can be increased, and the chance of light being absorbed can be increased. However, the superstrate structured thin film solar cell faces away from the transparent conductive layer. Because the entire thin film solar cell needs to be immersed in the acid solution when etching the concave and convex structure, the environmental control is not easy, which may cause the entire thin film solar cell to be scrapped. Based on the above problems, it is highly desirable to propose a thin film solar cell that can effectively absorb incident light and thereby improve photoelectric conversion efficiency.

Referring to U.S. Patent No. 5,213,628, it is incorporated herein by reference, which discloses the disclosure of the utility of the present invention to increase the carrier lifetime of a solar cell and reduce the electron-electron-composite probability by adding an amorphous germanium-essential semiconductor to improve the photocurrent conversion efficiency. However, this patent does not disclose how to increase the usage of incident light and the efficiency of the solar cell is too low, which also affects the scope of subsequent applications.

Referring to U. Similarly, this patent does not disclose the absorption of incident light, and the efficiency of the solar cell is too low, which also affects the scope of subsequent applications.

The job is the reason, the applicant is carefully experimenting and research, and a perseverance spirit, finally developed a thin film solar cell, especially related to a solar cell containing a layer of nano metal particles. With the nano metal particle layer, a thin film solar cell of the present invention can increase the capture of incident light and the utilization of light, thereby improving the photocurrent and power generation efficiency.

The main object of the present invention is to provide a thin film solar cell, which can increase the capture of incident light and the utilization of light by increasing the layer of nano metal particles, thereby improving the photocurrent and power generation efficiency.

A secondary object of the present invention is to provide a thin film solar cell which is formed by a layer of nano metal particles formed in a plurality of laser-treated trenches to improve photocurrent and power generation efficiency.

To achieve the above object, the present invention provides a thin film solar cell comprising: a substrate, a first transparent conductive layer, a P-type semiconductor layer, an intrinsic (i) type semiconductor layer, an N type semiconductor layer, a nano metal particle layer, and a second Transparent conductive layer and back electrode. Wherein, the first transparent conductive layer is formed on the substrate for taking out electrical energy; the P-type semiconductor layer is formed on the first transparent conductive layer for generating a hole; and the essential (i) type semiconductor layer is formed on the P On the semiconductor layer, for improving the absorption range of visible spectrum photons; the N-type semiconductor layer is formed on the essence (i) semiconductor layer for generating electrons; and the nano metal particle layer is formed on the N-type semiconductor layer, To increase the utilization of light; a second transparent conductive layer is formed over the nano metal particle layer; and a back electrode is formed on the second transparent conductive layer for extracting electrical energy.

The invention further provides a thin film solar cell comprising a substrate, a first transparent conductive layer, a P-type semiconductor layer, an intrinsic (i) type semiconductor layer, an N-type semiconductor layer, a second transparent conductive layer, a back electrode, a plurality of trenches and Nano metal particle layer. Wherein, the first transparent conductive layer is formed on the substrate for taking out electrical energy; the P-type semiconductor layer is formed on the first transparent conductive layer for generating a hole; and the essential (i) type semiconductor layer is formed on the P On the semiconductor layer, for improving the absorption range of visible spectrum photons; the N-type semiconductor layer is formed on the essence (i) semiconductor layer for generating electrons; the second transparent conductive layer is formed above the N-type semiconductor layer; An electrode formed on the second transparent conductive layer for extracting electrical energy; the plurality of trenches are processed through a laser to penetrate the back electrode, the second transparent conductive layer, the N-type semiconductor layer, and the essence The i) type semiconductor layer, the P type semiconductor layer and the first transparent conductive layer; and the nano metal particle layer are formed in the plurality of trenches, and the particle size of the nano metal particle layer is Between 5 and 200 nm, and the surface coverage of the particles of the nano metal particle layer in the grooves is 80% or less.

A thin film solar cell of the present invention has the following effects:

1. The nano metal particle layer of the invention can increase the capture of incident light and the utilization of light, thereby improving the photocurrent and power generation efficiency;

2. In the thin film solar cell of the present invention, by capturing the nano metal particles in the trench region after the laser treatment, the capture of the incident light and the utilization of the light can be increased, thereby improving the photocurrent and the power generation efficiency.

The above and other objects, features, and advantages of the present invention will become more apparent and understood.

While the invention may be embodied in various forms, the embodiments illustrated in the drawings It is not intended to limit the invention to the particular embodiments illustrated and/or described.

Referring now to FIG. 1, a schematic structural view of an embodiment of a thin film solar cell of the present invention is shown. The thin film solar cell 100 mainly includes a substrate 110, a first transparent conductive layer 120, a P-type semiconductor layer 130, an intrinsic (i) type semiconductor layer 140, an N-type semiconductor layer 150, a nano metal particle layer 160, and a second transparent conductive layer. Layer 170 and back electrode 180.

The substrate 110 is selected from the group consisting of a glass, a plastic substrate, a semiconductive substrate, an insulating substrate, a flexible substrate, or a stainless steel plate.

The first transparent conductive layer 120 is formed over the substrate 110 for taking out electrical energy. The first transparent conductive layer 120 is selected from the group consisting of indium oxide oxide (ITO), aluminum zinc oxide (AZO), fluorine-doped tin oxide film (FTO), tin oxide (SnO ₂ ), and zinc oxide (ZnO). And its thickness is between 200 nm and 800 nm. It should be noted that the preparation of different transparent conductive films affects the quality of the photoelectric properties they have. Preferably, a fluorine-doped tin oxide film (FTO) which is resistant to acid and alkali heat, moisture, and low in film forming raw materials and low in production cost is used.

The P-type semiconductor layer 130 is formed over the first transparent conductive layer 120 for generating a hole. Wherein, the P-type semiconductor layer 130 is defined by adding impurities to the original intrinsic material to generate excess holes, and forming a semiconductor layer of a majority carrier by a hole. Example: In the case of germanium or germanium semiconductors, in their intrinsic semiconductors, impurities doped with trivalent atoms form excess holes, making the hole act as a current.

An intrinsic (i) type semiconductor layer 140 is formed over the P-type semiconductor layer 130 for enhancing the absorption range of photons in the visible spectrum. Among them, the intrinsic (i) type semiconductor layer 140 has the greatest influence on the electrical characteristics of the thin film solar cell, because when the electron and the hole are conducted inside the material, if the thickness of the intrinsic (i) type semiconductor layer 140 is too thick, the probability of coincidence Extremely high, in order to avoid this phenomenon, the intrinsic (i) type semiconductor layer 140 should not be too thick. On the other hand, when the thickness of the (i) type semiconductor layer 140 is too thin, the light absorbing property is insufficient.

The N-type semiconductor layer 150 is formed over the intrinsic (i) semiconductor layer 140, which is used to generate electrons. The N-type semiconductor layer 150 refers to a semiconductor in which an impurity added to an intrinsic material generates excess electrons and electrons constitute a majority carrier, which is called an N-type semiconductor layer. For example, in the case of germanium or germanium semiconductors, if an intrinsic semiconductor is doped with impurities of a five-valent atom, excess electrons are formed, and electron current is the main mode of operation.

The P-type semiconductor layer 130, the intrinsic (i)-type semiconductor layer 140, and the N-type semiconductor layer 150 are prepared by a plasma enhanced chemical vapor deposition method, a hot wire chemical vapor deposition method, and an electron cyclotron resonance chemical vapor phase. One of deposition method, UHF plasma enhanced chemical vapor deposition method, low pressure chemical vapor deposition method, plasma assisted chemical vapor deposition and atmospheric pressure chemical vapor deposition. It is to be noted that the source of preparation of the P-type semiconductor layer 130, the intrinsic (i)-type semiconductor layer 140, and the N-type semiconductor layer 150 will affect the quality of its photoelectric characteristics.

A nano metal particle layer 160 is formed over the N-type semiconductor layer 150 for increasing the utilization of light. The nano metal particle layer 160 is selected from one of alloys of gold, silver, copper, platinum, nickel, zinc, tin, aluminum, and the preparation method of the nano metal particle layer 160 is selected from a sputtering method. One of vapor deposition method, electroplating method, chemical vapor deposition method, sol-gel method, spray lysis method, dipping method, spin coating method, screen printing method, and electrochemical method.

It is worth noting that the reason for increasing the utilization of light is that the surface plasma is formed by the surface characteristics of the nano metal, which will resonate with the incident light to increase the capture of the incident light and the utilization of light. Finally, the photocurrent is achieved. Increased power generation efficiency. On the other hand, at the same incident frequency, light cannot directly excite the surface plasma of the metal surface because their wave vectors do not match; however, when the metal is nano- or surface roughened, the wave vector and surface of the light will be made. When the wave vectors of the plasma are equal, the surface plasma of the metal surface can be excited, thereby increasing the utilization of light. Further, the nanoparticle particle layer 160 has a particle grain size of between 5 and 200 nm. Preferably, the nanoparticle particle layer 160 has a particle size between 20 and 50 nanometers. It should be noted that the nano metal particle layer 160 is not completely continuous film, but is composed of dispersed nano metal particles. Therefore, the surface coverage of the nanoparticle of the nano metal particle layer 160 in the surface of the N-type semiconductor layer 150 is between 20% and 60%, that is, the distribution density of the nano metal particles on the surface is 10 ⁶ to 10 ¹⁰ / m ² . Preferably, the surface coverage of the nanoparticles of the nano metal particle layer 160 in the N-type semiconductor layer 150 is between 50% and 60%; that is, the nano metal particles are in the N-type semiconductor layer 150. The surface distribution density is 10 ⁹ ~ 10 ¹⁰ /m ² . It should be noted that the nano metal particles can effectively enhance the photocurrent and photoelectric conversion efficiency when the surface distribution density is greater than 10 ⁶ /m ² .

The second transparent conductive layer 170 is formed over the nano metal particle layer 160. The second transparent conductive layer 170 is selected from one of indium tin oxide (ITO), aluminum zinc oxide (AZO), fluorine-doped tin oxide film (FTO), tin oxide (SnO ₂ ), and zinc oxide (ZnO), and Its thickness is between 200 nm and 800 nm. It should be noted that the preparation of different transparent conductive films affects the quality of the photoelectric properties they have.

The back electrode 180 is formed over the second transparent conductive layer 170 for taking out electrical energy. The back electrode 180 is selected from one of conductive materials such as nickel, gold, silver, titanium, palladium, platinum, and aluminum.

It should be noted that in another embodiment, the second transparent conductive layer 170 may be omitted. 2 is a schematic structural view of another embodiment of the thin film solar cell 100 of the present invention, which is substantially the same as FIG. 1 , and the main difference is that no second transparent conductive layer 170 can be omitted, that is, the nano metal is The particle layer 160 is directly deposited on the surface of the N-type semiconductor layer 150. The surface coverage of the nano metal particles in the N-type semiconductor layer 150 is between 20% and 90%, that is, the distribution density of the nano metal particles on the surface of the N-type semiconductor layer 150 is 10 ⁶ to 10 ¹³ /m ² .

Please refer to FIG. 3 , which is a schematic structural view of still another embodiment of the thin film solar cell 100 of the present invention. The thin film solar cell 100 mainly includes a substrate 110, a first transparent conductive layer 120, a P-type semiconductor layer 130, an intrinsic (i) type semiconductor layer 140, an N-type semiconductor layer 150, a nano metal particle layer 160, and a second transparent layer. Conductive layer 170 and back electrode 180. Roughly the same as the first embodiment, the main difference is that in this embodiment, the second transparent conductive layer 170 is formed on the N-type semiconductor layer 150, and then the nano metal particle layer 160 is formed in the second. On the transparent conductive layer 170. The nano metal particle layer 160 is not completely a continuous film, but is composed of a plurality of dispersed nano metal particles, wherein the nano metal particle layer 160 is selected from the group consisting of gold, silver, copper, platinum, nickel, zinc, tin, One of aluminum or one of alloys, and the preparation method of the nano metal particle layer 160 is selected from the group consisting of sputtering, evaporation, electroplating, chemical vapor deposition, sol-gel method, spray lysis method, and dipping method. One of spin coating, screen printing and electrochemical methods. Wherein, the grain size of the nano metal particle layer 160 is between 5 and 200 nm, and the surface coverage of the nano particles of the nano metal particle layer 160 is 20% to 90% on the surface of the second transparent conductive layer 170. The particles of the nano metal particle layer 160 are distributed on the surface of the second transparent conductive layer 170 at a density of 10 ⁶ to 10 ¹³ /m ² .

Please refer to FIG. 4, which illustrates still another embodiment of the thin film solar cell 200 of the present invention. This embodiment suggests that a layer of nano metal particles is formed between the plurality of trenches of the diced thin film solar cell. The thin film solar cell 200 mainly includes a substrate 210, a first transparent conductive layer 220, a P-type semiconductor layer 230, an intrinsic (i) type semiconductor layer 240, an N-type semiconductor layer 250, a second transparent conductive layer 260, and a back electrode 270. The substrate 210 is selected from the group consisting of a glass, a plastic substrate, a semiconductive substrate, an insulating substrate, a flexible substrate, or a stainless steel plate. The first transparent conductive layer 220 is formed over the substrate 210 for taking out electrical energy. The first transparent conductive layer 220 is selected from one of indium lanthanum oxide (ITO), aluminum zinc oxide (AZO), fluorine-doped tin oxide film (FTO), tin oxide (SnO ₂ ), and zinc oxide (ZnO), and The thickness is between 200 and 800 nm. It should be noted that the preparation of different transparent conductive films affects the quality of the photoelectric properties they have. Preferably, a fluorine-doped tin oxide film (FTO) which is resistant to acid and alkali heat, moisture, and low in film forming raw materials and low in production cost is used.

A P-type semiconductor layer 230 is formed over the first transparent conductive layer 220 for generating a hole. The definition of the P-type semiconductor layer 230 is that impurities are added to the original intrinsic material to generate excess holes, and the semiconductor layer of the majority carrier is formed by the holes. Example: In the case of germanium or germanium semiconductors, in their intrinsic semiconductors, impurities doped with trivalent atoms form excess holes, making the hole act as a current.

An intrinsic (i) type semiconductor layer 240 is formed over the P-type semiconductor layer 230 for enhancing the absorption range of photons in the visible spectrum. The intrinsic (i) type semiconductor layer 240 has the greatest influence on the electrical characteristics of the thin film solar cell. When the electron and the hole are conducted inside the material, if the thickness of the intrinsic (i) type semiconductor layer 240 is too thick, the probability of coincidence Extremely high, in order to avoid this phenomenon, the intrinsic (i) type semiconductor layer 240 should not be too thick. On the other hand, when the thickness of the (i) type semiconductor layer 240 is too thin, the light absorbing property is insufficient.

An N-type semiconductor layer 250 is formed over the intrinsic (i) semiconductor layer 240 for generating electrons. The N-type semiconductor layer 250 refers to a semiconductor in which an impurity added to an intrinsic material generates excess electrons and electrons constitute a majority carrier, which is called an N-type semiconductor layer. For example, in the case of germanium or germanium semiconductors, if an intrinsic semiconductor is doped with impurities of a five-valent atom, excess electrons are formed, and electron current is the main mode of operation.

The preparation method of the P-type semiconductor layer 230, the intrinsic (i) type semiconductor layer 240, and the N-type semiconductor layer 250 is selected from the group consisting of a plasma enhanced chemical vapor deposition method, a hot wire chemical vapor deposition method, and an electron cyclotron resonance chemical vapor phase. One of deposition method, UHF plasma enhanced chemical vapor deposition method, low pressure chemical vapor deposition method, plasma assisted chemical vapor deposition and atmospheric pressure chemical vapor deposition. It should be noted that the preparation source of the P-type semiconductor layer 230, the intrinsic (i)-type semiconductor layer 240, and the N-type semiconductor layer 250 may affect the quality of the photoelectric characteristics thereof.

The second transparent conductive layer 260 is formed over the N-type semiconductor layer 250. The second transparent conductive layer 260 is selected from one of indium lanthanum oxide (ITO), aluminum zinc oxide (AZO), fluorine-doped tin oxide film (FTO), tin oxide (SnO ₂ ), and zinc oxide (ZnO), and Its thickness is between 200 nm and 800 nm. It should be noted that the preparation of different transparent conductive films affects the quality of the photoelectric properties they have.

The back electrode 270 is selected from one of conductive materials such as nickel, gold, silver, titanium, palladium, platinum, and aluminum, and is formed over the second transparent conductive layer 260 for taking out electrical energy. It should be noted that the back electrode 270 includes a plurality of trenches formed by laser processing in order to avoid the occurrence of a short circuit, and the nano metal particle layer 280 is formed in the trenches. The first transparent conductive layer 220, the P-type semiconductor layer 230, the i-type semiconductor layer 240, the N-type semiconductor layer 250, and the second transparent conductive layer 260 may also include a plurality of trenches formed by laser processing. In detail, the first transparent conductive layer 220 forms a plurality of first trenches in a laser cutting manner, and divides the first transparent conductive layer 220 into a plurality of upper electrodes. Next, the P/i/N type semiconductor layers 230, 240, and 250 are formed to fill the first trenches on the upper electrode. Then, the P/i/N type semiconductor layers 230, 240, 250 are further laser-cut to form a plurality of second trenches, and the second trench exposes portions of the upper electrodes. Subsequently, a second transparent conductive layer 260 is formed and fills the second trenches. Next, a back electrode 270 is formed on the second transparent conductive layer 260. Finally, the back electrode 270 and the second transparent conductive layer 260 are laser-cut to form a plurality of third trenches 290. The plurality of third trenches 290 divide the thin film solar cell into a plurality of unit cells.

At this time, the nano metal particle layer 280 is distributed between the plurality of third trenches 290, and the particle size of the nano metal particle layer 280 is between 5 and 200 nm, and the nano metal is The particles should not be too large and not continuous, and the surface coverage is 80% or less to avoid conduction between the unit cells, that is, the distribution density of the nano metal particles on the surface is less than 10 ¹² /m ² . . The nano metal particle layer 280 is one selected from the group consisting of gold, silver, copper, platinum, nickel, zinc, tin, aluminum, or an alloy thereof, by sputtering, evaporation, electroplating, chemical vapor deposition, It is prepared by one of sol-gel method, spray lysis method, dipping method, spin coating method, screen printing method and electrochemical method.

It is worth noting that the surface plasma formed by the surface characteristics of the nano metal will resonate with the incident light to increase the capture of incident light and the utilization of light. Finally, the photocurrent and power generation efficiency are improved. On the other hand, at the same incident frequency, light cannot directly excite the surface plasma of the metal surface because their wave vectors do not match; however, when the metal is nano- or surface roughened, the wave vector and surface of the light will be made. When the wave vectors of the plasma are equal, the surface plasma of the metal surface can be excited, thereby increasing the utilization of light.

In addition, the structure disclosed in the present invention is applicable to amorphous germanium and microcrystalline germanium thin film solar cells. In addition, it can be applied not only to a single cell but also to a modular solar cell process.

<Example 1>

Please refer to Figure 1 first, first prepare a glass substrate with a length and width of 5 cm and 10 cm, and then deposit 300 nm of the FTO first transparent conductive layer, respectively, 10/250/10 nm. /i/N semiconductor layer, 50 nm silver nano metal particle layer, 300 nm SnO ₂ second transparent conductive layer, and 300 nm aluminum back electrode. The surface coverage of the silver nanoparticle layer on the N-type semiconductor layer 150 is 60%. Wherein, the silver nano metal particle layer is formed by sputtering. Under the illumination of the standard light source AM 1.5, the efficiency can be increased by 10% compared to the battery without the silver nano metal layer.

<Example 2>

The main difference between this embodiment and the embodiment 1 is that the first transparent conductive layer is changed to SnO ₂ , the second transparent conductive layer is changed to AZO, and the nano metal particle layer is changed to 20 nanometers of gold nano metal. The particle layer is formed by vapor deposition. The surface coverage of the gold nano metal particle layer on the N-type semiconductor layer 150 is 60%. Under the illumination of the standard light source AM 1.5, the efficiency can be increased by 15% compared to the battery which does not contain the layer of the gold nanoparticle.

<Example 3>

The main difference between this embodiment and the first embodiment is that the nano metal particle layer is changed to a 20 nm nanometer gold nanometer metal layer layer, which is formed by evaporation of the second transparent conductive layer. . The surface coverage of the silver nano metal particle layer on the second transparent conductive layer was 60%. Under the illumination of the standard light source AM 1.5, the efficiency can be increased by 12% compared to the battery which does not contain the layer of the gold nanoparticle.

<Example 4>

The main difference between this embodiment and the first embodiment is that there is no second transparent conductive layer, and the nano metal particle layer is a gold nano metal particle layer having a size of 50 nm, which is formed by vapor deposition. The surface coverage of the gold nano metal particle layer on the N-type semiconductor layer 150 is 60%. Under the illumination of the standard light source AM 1.5, the efficiency can be increased by 10% compared to the battery without the layer of gold nanoparticles.

<Example 5>

Please refer to Figure 2 first, first prepare a glass substrate with a length and width of 1.4 meters and 1 cm, and then deposit 300 nm of FTO first transparent conductive layer, respectively, 20/350/20 nm. The P/i/N semiconductor layer and the 300 nm SnO ₂ second transparent conductive layer and the 300 nm aluminum back electrode. Further, a silver nano metal having a grain size of 30 nm was formed in a trench formed by a plurality of laser processes. Under the illumination of the standard light source AM 1.5, the efficiency can be increased by 15% compared to the battery without the layer of gold nanoparticles.

In summary, the thin film solar cell of the present invention has the following effects:

1. The nano metal particle layer of the invention can increase the capture of incident light and the utilization of light, thereby improving the photocurrent and power generation efficiency;

2. With the thin film solar cell of the present invention, the trench formed by the laser treatment can be further utilized, and the nano metal particle layer is provided to increase the capture of the incident light and the utilization of the light in the trench, thereby achieving the photocurrent and Increased power generation efficiency.

While the present invention has been described in its preferred embodiments, it is not intended to limit the scope of the invention, and various modifications and changes can be made without departing from the spirit and scope of the invention. As explained above, various modifications and variations can be made without departing from the spirit of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

100. . . Thin film solar cell

110. . . Substrate

120. . . First transparent conductive layer

130. . . P-type semiconductor layer

140. . . Essential (i) type semiconductor layer

150. . . N-type semiconductor layer

160. . . Nano metal particle layer

170. . . Second transparent conductive layer

180. . . Back electrode

200. . . Thin film solar cell

210. . . Substrate

220. . . First transparent conductive layer

230. . . P-type semiconductor layer

240. . . Essential (i) type semiconductor layer

250. . . N-type semiconductor layer

260. . . Second transparent conductive layer

270. . . Back electrode

280. . . Nano metal particle layer

290. . . Trench

1 is a schematic structural view of an embodiment of a thin film solar cell of the present invention;

2 is a schematic structural view of another embodiment of a thin film solar cell of the present invention;

3 is a schematic structural view of still another embodiment of the thin film solar cell of the present invention;

Figure 4 is a schematic view showing the structure of still another embodiment of the thin film solar cell of the present invention.

100. . . Thin film solar cell

110. . . Substrate

120. . . First transparent conductive layer

130. . . P-type semiconductor layer

140. . . Essential (i) type semiconductor layer

150. . . N-type semiconductor layer

160. . . Nano metal particle layer

170. . . Second transparent conductive layer

180. . . Back electrode

Claims (8)

A thin film solar cell comprising: a substrate; a first transparent conductive layer formed on the substrate for extracting electrical energy; and a P-type semiconductor layer formed on the first transparent conductive layer for generating electricity a substantially (i)-type semiconductor layer formed on the P-type semiconductor layer for enhancing absorption range of visible spectrum photons; an N-type semiconductor layer formed on the essence (i) semiconductor layer for generating An electron; a nano metal particle layer formed on the N-type semiconductor layer for increasing light utilization; a second transparent conductive layer formed on the nano metal particle layer; and a back electrode formed on The second transparent conductive layer is used for extracting electric energy; wherein the particles of the nano metal particle layer are one selected from the group consisting of gold, silver, copper, platinum, nickel, zinc, tin, aluminum, or alloy. The grain size of the rice metal particle layer is between 5 and 200 nm, and the surface coverage of the nanoparticle of the nano metal particle layer is between 20% and 60%. The thin film solar cell of claim 1, wherein the method for preparing the nano metal particle layer is selected from the group consisting of sputtering, evaporation, electroplating, chemical vapor deposition, sol-gel, and spray lysis. , dipping method, spin coating method, screen printing method and electricity One of the chemical laws. A thin film solar cell comprising: a substrate; a first transparent conductive layer formed on the substrate for extracting electrical energy; and a P-type semiconductor layer formed on the first transparent conductive layer for use Forming a hole; an intrinsic (i) type semiconductor layer is formed on the P-type semiconductor layer for increasing the absorption range of visible spectrum photons; an N-type semiconductor layer is formed in the essence (i) a semiconductor layer for generating electrons; a second transparent conductive layer formed on the N-type semiconductor layer; a back electrode formed on the second transparent conductive layer for extracting electrical energy; Passing through a laser treatment to penetrate the back electrode, the second transparent conductive layer, the N-type semiconductor layer, the intrinsic (i) type semiconductor layer, the P-type semiconductor layer and the first transparent conductive layer; a layer of nano metal particles formed in the plurality of trenches, the particles of the nano metal particle layer being selected from one of an alloy or an alloy of gold, silver, copper, platinum, nickel, zinc, tin, aluminum, The particle size of the nano metal particle layer is between 5 and 200 The surface coverage of the particles of the nano metal particle layer in the grooves between the nanoparticles is 80% or less. The thin film solar cell of claim 3, wherein the method for preparing the nano metal particle layer is selected from the group consisting of sputtering, evaporation, electroplating, chemical vapor deposition, sol-gel, and spray lysis. One of the impregnation method, the spin coating method, the screen printing method, and the electrochemical method. A thin film solar cell comprising: a substrate; a first transparent conductive layer formed on the substrate for extracting electrical energy; and a P-type semiconductor layer formed on the first transparent conductive layer for generating electricity a substantially (i)-type semiconductor layer formed on the P-type semiconductor layer for enhancing absorption range of visible spectrum photons; an N-type semiconductor layer formed on the essence (i) semiconductor layer for generating a second transparent conductive layer formed on the N-type semiconductor layer; a nano metal particle layer formed on the second transparent conductive layer for increasing light utilization; and a back electrode formed on The nano metal particle layer is used for extracting electric energy; wherein the particle of the nano metal particle layer is one of alloy or alloy selected from the group consisting of gold, silver, copper, platinum, nickel, zinc, tin, and aluminum. The grain size of the rice metal particle layer is between 5 and 200 nm, and the surface coverage of the nanoparticle of the nano metal particle layer is between 20% and 90%. The thin film solar cell according to claim 5, wherein the method for preparing the nano metal particle layer is selected from the group consisting of a sputtering method, an evaporation method, an electroplating method, a chemical vapor deposition method, a sol-gel method, and a spray cleavage method. One of the impregnation method, the spin coating method, the screen printing method, and the electrochemical method. A thin film solar cell comprising: a substrate; a first transparent conductive layer formed on the substrate for extracting electrical energy; and a P-type semiconductor layer formed on the first transparent conductive layer for generating electricity a substantially (i)-type semiconductor layer formed on the P-type semiconductor layer for enhancing absorption range of visible spectrum photons; an N-type semiconductor layer formed on the essence (i) semiconductor layer for generating An electron; a nano metal particle layer formed on the N-type semiconductor layer for increasing light utilization; and a back electrode formed over the nano metal particle layer for extracting electrical energy; wherein the nano The particles of the metal particle layer are selected from one of alloys of gold, silver, copper, platinum, nickel, zinc, tin, aluminum, and the grain size of the nano metal particle layer is between 5 and 200 nm. And the nano metal particle layer of nano The surface coverage of the particles on the N-type semiconductor layer is between 20% and 90%. The thin film solar cell according to claim 7, wherein the method for preparing the nano metal particle layer is selected from the group consisting of a sputtering method, an evaporation method, a plating method, a chemical vapor deposition method, a sol-gel method, and a spray cleavage method. One of the impregnation method, the spin coating method, the screen printing method, and the electrochemical method.