Disorder and defects in sputtered a-SiH from subgap absorption measurements

Abstract

The subgap optical absorption has been measured by photothermal deflection spectroscopy in undoped sputtered a-SiH films deposited at substrate temperatures between R.T. and 450°C. In contrast with the results on glow discharge materials the integrated defect density NR does not generally scale with the ESR dangling bond density. Comparison of the PDS data with I.R. spectroscopy results shows that both NR and the Urbach slope Eo are determined by the short range order as these parameters are correlated with the relative variations of the 2095 cm-1 I.R. absorption line in the stretching mode doublet. © 1985.