Solar Thermal Annealing Of The Preparation Of Polycrystalline Silicon Thin Film

Solar cell as one kind of green energy resource exhibits important role in the condition of the resource crisis and environmental crisis today. Polycrystalline silicon thin film solar cell possesses the excellence of both crystalline silicon solar cell and amorphous thin film silicon solar cell. It is one of the most preponderant candidates of the second generation solar cells.As the grain size of polycrystalline silicon thin film augments, the conversion efficiency of solar cell increases. But the grain size of silicon thin film directly deposited is small; it needs to be increased with recrystallization techniques. At present the main recrystallization techniques employed at home and abroad include conventional furnace annealing, rapid photo-thermal annealing (RPTA), metal-induced crystallization, microwave-induced crystallization, and laser crystallization and so on. This paper mostly research using photo-thermal annealing to prepare polycrystalline silicon thin film.Amorphous silicon thin films were deposited with PECVD method, and then annealed using photo-thermal annealing.Firstly, it revealed the influences of anneal and deposition parameters, those were the calefactive velocity, the cooling velocity, the substrate temperature and doping on the crystalline. It showed that: (1) the calefactive velocity influenced the generation density of crystal seeds. When the temperature changed rapidly, many seeds couldn't grow up. In this instance, the big grain of polycrystalline silicon thin film would be obtained. (2)In cooling process, when the temperature changed rapidly, the small particle would be obtained resembling the quencher. (3) In the deposited process , a-Si:H thin films deposited at 300℃ were easier to be crystallized than those deposited at 100℃.(4) Phosphorus doping speeded the crystallization of amorphous silicon thin film.The meaning of the high quality poly-Si film prepared at lower temperature and in shorter time is more important, because lower cost substrate material can be chosen at lower temperature. So based on the mechanism analysis of rapid photo-thermal...