Thin-Film Silicon –Growth Process and Solar Cell Application–

Growth processes of hydrogenated amorphous silicon (a-Si:H) and microcrystalline silicon (µc-Si:H) from SiH 4 and H 2 /SiH 4 -glow discharge plasmas are reviewed. Differences and similarities between µc-Si:H and a-Si:H growth reactions in the plasma and on the film-growing surface are discussed, and the nucleus-formation process followed by the epitaxial-like crystal growth process is explained as being processes unique to µc-Si:H. The governing reaction of dangling-bond-defect density in the resulting a-Si:H and µc-Si:H films is also discussed in order to obtain a clue to improve the optoelectronic properties of these materials to enable device applications, particularly to thin-film silicon-based solar cells. Material issues concerning the realization of low-cost high-efficiency solar cells are described, and finally, recent progress in those issues is presented.