Preparation of polycrystalline silicon thin film for solar cells on glass by aluminum-induced layer exchange

Polycrystalline silicon films were prepared by aluminum-induced layer exchange (ALILE). The films deposited by vacuum evaporation were initially amorphous and then transformed into polycrystalline state in the process of ALILE. The mechanism of ALILE was given briefly in the paper. The morphology of the samples was studied using AFM. It was found that substrate distances significantly affect the morphology of the samples and the optimum substrate distance was around 90 mm. The crystalline quality of the films was examined using Raman spectroscopy, and it turned out that substrate temperature and annealing temperature were critical parameters for the crystalline volume fraction of the films. The crystalline volume fraction reached 89% at substrate temperature of 450 °C and annealing temperature of 500 °C.

► Polycrystalline silicon thin films were prepared by both vacuum evaporation and aluminum-induced layer exchange.
► Compared to ELC, PECVD, SPC and other methods, this method is simpler, more environmental-friendly and less-time consuming.
► Substrate distance significantly influenced the morphology and the crystalline volume fractions of the films.