STUDY ON CAT-CVD POLY-SI FILMS FOR SOLAR-CELL APPLICATION

Feasibility of polycrystalline silicon (poly-Si) films deposited by ca talytic CVD (cat-CVD) method as a solar cell material is studied. The poly-Si films are obtained at 300 degrees C by catalytic cracking reac tions of a gaseous mixture of SiH4 and H-2 on a heated tungsten (W) wi re. Present poly-Si films consist of both amorphous and polycrystallin e phases. The mixing ratio of amorphous to polycrystalline phases can be controlled by deposition conditions. Because of both large optical absorption and relatively large mobility of carrier transport, a cat-C VD poly-Si film is a feasible candidate for solar cell material.