Abstract:

Polycrystalline silicon (poly-Si) thin films solar cells have been one of the thin-film solar cells with the greatest development potential. In the development of poly-Si thin-film solar cells , a key point is to fast deposit large and high-quality poly-Si thin films. Iri this paper , poly-Si thin films with large grains were prepared via the Rapid Thermal-Chemical Vapor Deposition (RTCVD) , with SiHC13 as the silicon source and B2H6 as the doping
gas. Thin films with a thickness of 30 - 40μm and a deposition rate of 3 - 7μm/min were thus obtained. The effect of deposition temperature on the growth rate of the film and the microstructure of the crystal was then investigated. It is concluded that , with the increase in deposition temperature from 900 to 1170℃ , the average growth rate ap-proximately exhibits a monotonous increase , the average crystal size increases from less than 3μm at 900℃ to more than 30μm at 1170℃, and the deposition is controlled by the surface reaction mechanism. Moreover , the poly-Si thin films tend to grow in [220] direction at low temperature while in [111] preferred orientation when the tem-perature reaches 1170℃ .

Key words: polycIγstalline silicon, thin film, deposition temperature, crystal growth, crystal orientation, solar cell