Structure and photoelectric properties of hydrogenated amorphous silicon-germanium alloys produced by high hydrogen dilution method

Abstract

A series of hydrogenated amorphous silicon-germanium alloys have been fabricated by high hydrogen dilution method. The Ge content in the film increases from 0.4 to 0.8 and the corresponding optical bandgap is in the range of 1.48-1.22 eV. The photoconductivity is 3.6 × 10-6 S/cm and photosensitivity is as high as 7.3 × 103 at an optical bandgap of 1.48 eV. The deterioration of photoelectric properties with increasing Ge content could be attributed to the decrease of the bonded hydrogen content and the inhomogeneous structure in the alloy network.