Thin-film solar cell

Abstract

The utility model relates to the technical field of solar cells, and discloses a thin-film solar cell, which comprises a substrate, a reflection enhancement layer arranged above the substrate, a metal reflection layer arranged above the reflection enhancement layer, a transparent conductive oxide layer arranged above the metal reflection layer, and a transparent conductive layer arranged above the transparent conductive oxide layer. A transparent conductive oxide layer is arranged on the thin film solar cell, a light absorption enhancement layer is arranged on the transparent conductive oxide layer, a semiconductor layer is arranged on the light absorption enhancement layer, a front electrode is arranged on the semiconductor layer, and a glass packaging layer is arranged on the front electrode. The reflection frequency of light on the surface or in the material is increased through the reflection enhancement layer formed by the multiple layers of dielectric reflection films and the metal reflection layer, so that the overall reflection effect is enhanced, the light loss is reduced, and the photoelectric conversion efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of solar cell wafers, in particular to a thin-film solar cell wafer. Background Technique

[0002] The thin-film solar cell wafer is a new type of photovoltaic device, which is characterized by being thin, flexible and having a relatively low cost. The working principle of the thin-film solar cell is based on the photovoltaic effect, that is, when light irradiates certain materials, voltage or current can be generated. Compared with traditional crystalline silicon solar cells, the main advantages of thin-film solar cells are their simple manufacturing process, low cost and the ability to be made into various shapes and sizes. The basic structure of the thin-film solar cell consists of multiple layers, and each layer undertakes a specific function and works together to achieve the goal of effectively converting light energy into electrical energy. The typical structure includes a substrate, a metal layer, a transparent conductive layer, a semiconductor layer, etc. from bottom to top in sequence.

[0003] The existing Chinese patent (CN210040218U) discloses a thin-film solar cell wafer, which includes a solar cell wafer main body. The solar cell wafer main body includes an aluminum foil panel, a zinc oxide layer, a chemical vapor deposition layer, a double-layer prefabricated polyester film, a glass powder layer, a glass backplane and aluminum-based contact bumps. The aluminum foil panel is located on the upper surface of the solar cell wafer main body, the zinc oxide layer is located on the lower surface of the aluminum foil panel, the chemical vapor deposition layer is located on the lower surface of the zinc oxide layer, and aluminum-based contact bumps are arranged at both ends of the upper surface of the aluminum foil panel.

[0004] In the above technical solution, the aluminum foil panel is used as the substrate and reflection layer of the thin-film solar cell wafer. However, the aluminum foil panel is prone to deformation and cannot well meet the requirements of long-term use, and the reflection efficiency is relatively low, making it difficult to make full use of light. This means that a large amount of solar energy resources are not effectively converted into electrical energy, thus reducing the performance of the solar cell panel. Content of the Utility Model

[0005] The purpose of the utility model is to provide a thin-film solar cell wafer to solve the problems raised in the above background technique.

[0006] To achieve the above purpose, the utility model provides the following technical solution: a thin-film solar cell wafer, including a substrate, a reflection enhancement layer is arranged above the substrate, a metal reflection layer is arranged above the reflection enhancement layer, a transparent conductive oxide layer is arranged above the metal reflection layer, a light absorption enhancement layer is arranged above the transparent conductive oxide layer, a semiconductor layer is arranged above the light absorption enhancement layer, a front electrode is arranged above the semiconductor layer, and a glass encapsulation layer is arranged above the front electrode.

[0007] Further, the semiconductor layer includes a P-type semiconductor layer, the P-type semiconductor layer is located above the light absorption enhancement layer, an active layer is provided above the P-type semiconductor layer, and an N-type semiconductor layer is provided above the active layer.

[0008] Further, a surface plasmon texture structure is provided on the upper surface of the active layer, and the active layer is used to absorb sunlight and convert light energy into electrical energy.

[0009] Further, the reflection enhancement layer is a multi-layer dielectric reflection film, and the metal reflection layer is a molybdenum layer.

[0010] Further, the transparent conductive oxide layer is any one of an indium tin oxide layer or a fluorine-doped tin oxide layer.

[0011] Further, the light absorption enhancement layer is a periodic metal grating.

[0012] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0013] By providing the reflection enhancement layer, the metal reflection layer and the light absorption enhancement layer, the present utility model realizes that when the thin-film solar cell is in use, when sunlight irradiates the solar cell, photons will be absorbed by the semiconductor layer. Near the PN junction, when the photon energy is large enough, electrons will be excited to jump from the valence band to the conduction band, forming electron-hole pairs. Due to the electric field of the PN junction, electrons and holes will move to the N region and the P region respectively, forming a photocurrent. Through the transparent conductive oxide layer and the front electrode, these currents can be collected and led out to the external circuit, thereby generating electrical energy. During the process of generating electrical energy in the thin-film solar cell, the reflection enhancement layer composed of the multi-layer dielectric reflection film and the metal reflection layer increase the number of reflections of light on the surface or inside the material, thereby enhancing the overall reflection effect, reducing light loss and improving the photoelectric conversion efficiency. Description of the Drawings

[0014] Figure 1 is a perspective view of a thin-film solar cell of the present utility model;

[0015] Figure 2 is a perspective view of another angle of a thin-film solar cell of the present utility model;

[0016] Figure 3 is a front view of a thin-film solar cell of the present utility model;

[0017] Figure 4 is a left view of a thin-film solar cell of the present utility model.

[0018] In the figure: 1. Substrate; 2. Reflection enhancement layer; 3. Metal reflection layer; 4. Transparent conductive oxide layer; 5. Light absorption enhancement layer; 6. Semiconductor layer; 7. Front electrode; 8. Glass encapsulation layer; 601. P-type semiconductor layer; 602. Active layer; 603. N-type semiconductor layer. Detailed implementation manners

[0019] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0020] Please refer to Figures 1 - 4 , the present invention provides a technical solution: a thin-film solar cell, including a substrate 1, a reflection enhancement layer 2 is provided above the substrate, a metal reflection layer 3 is provided above the reflection enhancement layer 2, a transparent conductive oxide layer 4 is provided above the metal reflection layer 3, a light absorption enhancement layer 5 is provided above the transparent conductive oxide layer 4, a semiconductor layer 6 is provided above the light absorption enhancement layer 5, a front electrode 7 is provided above the semiconductor layer 6, and a glass encapsulation layer 8 is provided above the front electrode 7.

[0021] The semiconductor layer 6 includes a P-type semiconductor layer 601, the P-type semiconductor layer 601 is located above the light absorption enhancement layer 5, an active layer 602 is provided above the P-type semiconductor layer 601, and an N-type semiconductor layer 603 is provided above the active layer 602. The active layer material of the solar cell can be an organic material, an inorganic material or a composite material. For example, the active layer of an organic / polymer solar cell is composed of a blend of a donor material and an acceptor material, and these materials work together to improve the photoelectric conversion efficiency. In a traditional silicon-based solar cell, the active layer material is a semiconductor material such as silicon Si. The silicon material has a moderate bandgap and can absorb a relatively wide spectral range.

[0022] The upper surface of the active layer 602 is provided with a surface plasmon texture structure. The active layer 602 is used to absorb sunlight and convert light energy into electrical energy. By using fluorine-based plasma treatment, a very small amount of silicon on the upper surface of the active layer of the solar cell is removed. After the treatment, the upper surface can form 100% diffuse reflection and exhibit a total scattering phenomenon. At this time, photons pass through the active layer at an average angle of 60°, and the propagation path length is increased by two times. For example, an active layer originally 20 μm thick is optically equivalent to 40 μm thick. The main purpose of the surface plasmon texture treatment is to optimize the upper surface structure of the active layer, enhance the performance of the thin-film solar cell by increasing light scattering, and thus improve the photoelectric conversion efficiency.

[0023] The reflection enhancement layer 2 is a multi-layer dielectric reflection film. By adjusting its material and thickness, the reflection enhancement layer enables light to undergo multiple reflections between the multi-layer structures. These reflected lights are superimposed on each other, enhancing the overall reflection intensity. The multi-layer dielectric reflection film can utilize the refractive index difference between different materials to cause total internal reflection of light at the interface, thereby increasing the reflectivity. The metal reflection layer 3 is a molybdenum layer. The molybdenum layer is usually prepared by magnetron sputtering technology to ensure its uniformity, density, and good electrical conductivity.

[0024] The transparent conductive oxide layer 4 is either an indium tin oxide doped layer or a fluorine tin oxide doped layer. As the transparent electrode of the battery, it allows light to pass through and collects the generated current. Indium tin oxide or fluorine tin oxide doped layers have good electrical conductivity and light transmittance.

[0025] The light absorption enhancement layer 5 is a periodic metal grating. The surface plasmon resonance effect can be utilized to enhance the absorption of light near the metal-semiconductor interface, increasing the light absorption efficiency of the battery.

[0026] When the thin-film solar cell is in use, when sunlight shines on the solar cell, photons are absorbed by the semiconductor layer 6. Near the PN junction, when the photon energy is large enough, it will excite electrons to jump from the valence band to the conduction band, forming electron-hole pairs. Due to the electric field effect of the PN junction, electrons and holes will move to the N region and P region respectively, forming a photocurrent. Through the transparent conductive oxide layer 4 and the front electrode 7, these currents can be collected and led out to the external circuit, thereby generating electrical energy. During the process of generating electrical energy in the thin-film solar cell, the reflection enhancement layer 2 composed of the multi-layer dielectric reflection film and the metal reflection layer increase the number of reflections of light on the surface or inside the material, thereby enhancing the overall reflection effect, reducing the loss of light, and improving the photoelectric conversion efficiency.

[0027] Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

Claims

1. A thin-film solar cell, comprising a substrate (1), characterized in that: Above the substrate, there is a reflection enhancement layer (2). Above the reflection enhancement layer (2), there is a metal reflection layer (3). Above the metal reflection layer (3), there is a transparent conductive oxide layer (4). Above the transparent conductive oxide layer (4), there is a light absorption enhancement layer (5). Above the light absorption enhancement layer (5), there is a semiconductor layer (6). Above the semiconductor layer (6), there is a front electrode (7). Above the front electrode (7), there is a glass encapsulation layer (8).

2. A thin-film solar cell according to claim 1, characterized in that: The semiconductor layer (6) includes a P-type semiconductor layer (601). The P-type semiconductor layer (601) is located above the light absorption enhancement layer (5). Above the P-type semiconductor layer (601), there is an active layer (602). Above the active layer (602), there is an N-type semiconductor layer (603).

3. A thin-film solar cell according to claim 2, characterized in that: The upper surface of the active layer (602) is provided with a surface plasmon texture structure. The active layer (602) is used to absorb sunlight and convert light energy into electrical energy.

4. A thin-film solar cell according to claim 1, characterized in that: The reflection enhancement layer (2) is a multi-layer dielectric reflection film. The metal reflection layer (3) is a molybdenum layer.

5. A thin-film solar cell according to claim 1, characterized in that: The transparent conductive oxide layer (4) is either an indium tin oxide doped layer or a fluorine tin oxide doped layer.

6. A thin-film solar cell according to claim 1, characterized in that: The light absorption enhancement layer (5) is a periodic metal grating.

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