Structual and optoelectronic properties of polycrystalline silicon thin films p repared by hot-wire chemical vapor deposition at low temperatures

Polycrystalline silicon thin films were prepared by hot-wire chemical vapor deposition (HWCVD) on glass at 250℃，with W or Ta wire as the catalyzers. The structual and optoelectronic properties as functions of the filament temperature, deposition pressure and the filament-substrate distance were studied，and the optimized polycrystalline silicon thin films were obtained with Xc>90% (Xc denotes the crystalline ratio of the film), crystal grain size ab out 30—40nm, Rd≈0.8nm/s, σd about 10-7—10-6 Ω-1cm-1,Ea≈0.5eV and Eopt≤1.3eV.