Effect of Ge atoms on crystal structure and optoelectronic properties of hydrogenated Si–Ge films

Abstract

Optoelectronic and structural properties of hydrogenated microcrystalline silicongermanium (µc-Si 1−x Gex:H) alloys prepared by radio-frequency plasma-enhanced chemical vapor deposition (RF-PECVD) were investigated. When the Ge atoms were predominantly incorporated in amorphous matrix, the dark and photo-conductivity decreased due to the reduced crystalline volume fraction of the Si atoms (X Si-Si ) and the increased Ge dangling bond density. The photosensitivity decreased monotonously with Ge incorporation under higher hydrogen dilution condition, which was attributed to the increase in both crystallization of Ge and the defect density.