Amorphous silicon solar cells are thin-film solar cells based on amorphous silicon compounds. According to different materials, current silicon solar cells can be divided into three categories: monocrystalline silicon solar cells, polycrystalline silicon thin film solar cells and amorphous silicon thin film solar cells.
Advantages of amorphous solar cells
1. Low production cost: Due to the low reaction temperature, it can be manufactured at a temperature of about 200 °C, so films can be deposited on glass, stainless steel plates, ceramic plates, and flexible plastic sheets, which are easy to produce in large areas and have low costs.
2. Short energy return period: Amorphous silicon solar cells with a conversion efficiency of 6% use about 1.9 kWh/W of electricity for production, and the time to return the above energy after generating electricity is only 1.5-2 years.
3. Suitable for mass production: Amorphous silicon material is formed by vapor deposition, and the commonly used method is plasma enhanced chemical vapor deposition (PECVD) method. This manufacturing process can be continuously completed in multiple vacuum deposition chambers, thereby realizing mass production. The main process (PECVD) of amorphous silicon solar cells using glass substrates is similar to that of TFT-LCD array production, and the production methods have the characteristics of high degree of automation and high production efficiency.
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 hot wire method. In particular, the radio frequency glow discharge method has become an internationally recognized mature technology because of its low temperature process (~200 °C), which is easy to achieve large-scale and large-scale continuous production.
4. Good high temperature performance: when the working temperature of the solar cell is higher than the standard test temperature of 25 °C, its optimal output power will decrease; the temperature of the amorphous silicon solar cell is much less affected by the temperature than the crystalline silicon solar cell.
5. Good response to weak light and high charging efficiency: The absorption coefficient of amorphous silicon material is in the entire visible light range, and it has a good adaptability to low light and strong light in actual use.
The above-mentioned unique technical advantages make thin-film silicon cells have broad application prospects in the civilian field, such as photovoltaic building integration, large-scale low-cost power stations, and solar lighting sources.
Disadvantages of amorphous silicon solar cells
The industry has had doubts about amorphous silicon thin-film solar cells before, mainly because of their low cell conversion efficiency (5%-9%), and extremely fast decay, with a limited service life of only 2-3 years.
With the advancement of technology, the current mainstream amorphous silicon thin film solar cells have a service life of more than 10 years. This makes amorphous silicon thin-film solar cells one of the most promising thin-film cell technologies at present.