Study on the properties of nanocrystalline silicon formed by aluminum-induced crystallization at low temperature
WANG Jian-jun, GAO Fei, LIU Wei, FANG Xiao-ling
(College of Physics and Information Technology, Shaanxi Normal University, Xi′an 710062, Shaanxi, China)
Abstract:
Nanocrystalline silicon (nc-Si) is formed by aluminum-induced crystallization(AIC) of amorphous silicon at low temperatures (≤350℃) with a stack of glass/a-Si∶H/Al. The structure and optical properties of the AIC sample are analyzed by X-ray diffraction, Raman and UV-Vis-NIR spectrum. The results shown that with increasing annealing ramp-up time the crystalline volume fraction (Xc) and the optical absorption coefficient(α) increase, the si grain size (about 8 nm) remains unchanged. For the oxide film between the Al and the a-Si∶H layer is thin, which leads to a stronger interdiffusion between Al and Si, the nucleation density of silicon is considerably high. Besides, the Al atoms diffused into a-Si∶H film during AIC process and this enhanced the optical absorption of a-Si∶H film.
KeyWords:
amorphous silicon; nanocrystalline silicon; aluminum-induced crystallization; Raman spectrum
