Amorphous silicon (a-Si) solar cells deposit a transparent conductive film (TCO) on a glass substrate, then use a plasma reaction to deposit p-type, i-type, and i-type layers. n in sequence. .a-Si, then evaporate the metal electrode to aluminum (Al). Light comes from the glass surface and battery current is drawn from the transparent conductive film and aluminum. Its structure can be expressed as glass/TCO/pin/. Al. Stainless steel sheets, plastic as substrate. Silicon is the dominant material for solar cells. Silicon represents almost 40% of the cost of finished solar cells. However, the thickness of amorphous silicon solar cells is less than 1 μm, less than 1/100 of that. thickness of crystalline silicon solar cells. The manufacturing cost is significantly reduced and, as the manufacturing temperature of amorphous silicon solar cells is very low (~ 200 ° C) and it is easy to produce large areas, it occupies a leading position in thin film solar cells. In terms of manufacturing methods, there are electron cyclotron resonance method, photochemical vapor deposition method, DC glow discharge method, radio frequency glow discharge method, sputtering method and wire method. hot, etc. In particular, the radio frequency glow discharge method can easily achieve continuous production on large areas and large volumes thanks to its low temperature process (~200 °C), and has now become a mature technology recognized at the international. In terms of materials research, a-SiC window layer, gradient interface layer, μC-SiC p layer, etc. were studied successively, which significantly improved the shortwave spectral response ofe the battery due to the generation of photogenerated. The carriers of a-Si solar cells are mainly in the i layer, the incident light is partially absorbed by the p layer before reaching the i layer, which is inefficient for power generation. The a-SiC and μC-SiC materials have a wider optical band. larger than p-type a-Si, thus reducing the impact on light. Absorption increases light reaching the i-layer, coupled with the use of gradient interface layers, the photoelectron transport characteristics at the a-SiC/a-Si heterojunction interface; are improved in terms of increasing long-wave response, textured TCO films, multi-layer retro-reflective electrode with textured surface (ZnO/Ag/Al) and stacked structure with multiple band gaps, namely glass/TCO /p1i1n1/p2i2n2/p3i3n3/ZnO. Structure /Ag/Al. The textured TCO film and the multi-layer rear reflective electrodee reduce the reflection and transmission loss of light and increase the light propagation distance in layer i, thereby increasing the absorption of light in layer i. In the multiple bandgap structure, the bandgap width of layer i decreases sequentially from the light incident direction. In order to absorb sunlight in sections, the purpose of broadening the spectral response and improving the conversion efficiency is achieved. In terms of improving the efficiency of tandem cells, gradient band gap designs, microcrystalline doping layers in tunnel junctions, etc. are also used to improve carrier collection.
Solar cells now include several technologies such as crystalline silicon, thin film and CIGS.
Usually, solar cells mainly refer to silicon cells.crystalline icium. To use crystalline silicon as a base material, cut the silicon wafer into very thin slices, then print electrodes to make photovoltaic cells. According to the composition of crystalline silicon, it can be divided into monocrystalline silicon and polycrystalline silicon. There are many manufacturers of this technology.
Thin film batteries are very different in terms of materials and processes. The glass substrate is covered with a film, and then laser engraving is used to make cells, which can become amorphous silicon. It transmits light, unlike crystalline silicon which is opaque. However, the energy production per unit area is lower than that of crystalline silicon. There are not many manufacturers of this technology in the world. Hanergy in China is the largest, and First Solar in the United States is also a large company.
CIGSand miasole are another technology that can be transformed into flexible. and foldable drum sheets. The base material is a very thin steel sheet, which can withstand large bends. This is the biggest advantage of glass solar modules. It is also lightweight and easy to carry. This technology was invented by an American company and is now fully acquired by Hanergy. It can be said that this technology now belongs to Chinese companies.