Solar Cells With Polysilicon Films

Over years, with the concept of sustainable development and environmental protection deeply rooting among the people and gradual exhaustion of ordinary petrifaction energy sources, the main research task of solar cell focuses on how to replace the energy source. But in view of the limited reduction space upon cost of solar cell of silicon wafer, it is hard to compete with conventional energy. The cost of silicon wafer accounts for over 95% of overall costs of solar cell raw material and energy consumption. Therefore, the main way to reduce the cost of solar cell is to manufacture thin film cell. The article emphasizes the fabrication technology of polycrystalline thin films of solar cell and makes research on the preparation method of polycrystalline thin films, rapid photo-thermal annealing under low temperature (RPTA) and rapid thermal chemical vapor deposition (RTCVD) on ceramic substrate under high temperature, growth of silicon film as well as zone-melting recrystallization (ZMR), attempts of solar cell on ceramic substrate by means of high temperature and makes exploration on new method of layer transfer under high temperature.1. Plasma enhanced chemical vapor deposition (PECVD) is one of the matured and simple manipulated among the thin film deposition methods at low temperature. Chapter 2 in this article makes certain research on polycrystalline silicon thin films of PECVD and analyzes the growth principle, regularity and substrate performance of silicon thin film. The influences of deposition parameters include temperature, substrate, radio frequency power, ratio of SiH4 and doping on the crystalline and electric character was studied systematically.2 Solid Phase crystallization (SPC) is main re-crystallization techniques. Chapter 3 in this article makes certain research on Solid Phase crystallization (SPC), especially on rapid photo-thermal annealing (RPTA) technique. Two series of experiment were performed.The first series of experiment is that the light intensity is automatically adjusted to produce the predefined thermal cycle, controlled by a K-type thermocouple set on the silicon wafer. It was found that when the temperature is below 700 degrees centigrade, it is very difficult for a-Si:H thin films to crystallize. When annealing temperature is above 750 degrees centigrade, it is very ease for a-Si:H thin films to crystallize. That is to say, there exists a temperature transition field between 700 to 750 degrees centigrade. Then the crystallization condition of a-Si:H was studied thoroughly when it is above 750 degrees centigrade and below 700 degrees centigrade. The results turned out that annealing temperature and time have great influence on particle size and dark conductivity. There exists the best annealing condition of a-Si:H thin films. In addition, the influence of using conventional furnace annealing to warm up before photo-thermal annealing and the substrate temperature when a-Si:H film was deposited on the crystallization of a-Si:H thin films was also studied. It was found that to use normal high temperature stove to warm up before photo-thermal annealing is helpful to increase the size of polycrystalline silicon...