Studies on PECVD grown a SiGe:H alloys

We have grown amorphous hydrogenated silicon germanium (a-SiGe:H) alloys by plasma enhanced chemical vapour deposition (PECVD) varying the Ge content from 0 to 100%. The film composition was determined by EDAX. The films were characterised by measurement of optical Tauc gap, dark (σ dark ) and photoconductivity (σ ph ) and conductivity activation energy (ΔE) Photothermal deflection spectroscopy (PDS) measurements were done to determine the slope of the Urbach tail. Variation of film properties as a function of deposition parameters was studied.