Electric and Optical Properties of μc-Si,Ge:H Alloys Deposited by Reactive Magnetron Sputtering (RMS)

Abstract

Amorphous and microcrystalline silicon-germanium alloys, a-SixGel.x:H and gtc-SixGel.x:H, respectively, have been prepared by reactive magnetron sputtering (RMS) from pure crystalline Si and Ge targets in a hydrogen ambient using argon as the sputtering gas. We have investigated the structural, optical, and electronic properties of the as-deposited films. The optical and electrical properties, e.g., the ambipolar diffusion length, photoconductivity, and photosensitivity, were found to be comparable to those of device-grade a-SixGeI.x:H alloys, e.g., films with x-0.5, and band-gaps -1.3-1.4 eV. In contrast to the behavior of the a-SixGel-x:H alloys, the pjc-SixGei1x:H alloys do not display a Staebler-Wronski effect, as manifested by a decay of the photoconductivity under intense illumination.