Analysis of frequency-dependent loss data in amorphous silicon and germanium

Abstract

Abstract Loss peaks are observed in both the real and imaginary parts of the a.c. conductivity of a-Si and a-Ge samples at around liquid nitrogen temperatures. The data is plotted in a way suggested by a recent scaling theory which yields almost universal curves for the loss peaks. The decay length α+1 is the only adjustable parameter involved in the comparison between theory and experiment. Good agreement is obtained with α+1 = 1·5 nm for a pure a-Si sample and with α+1 decreasing from 2·5 to 0·25 nm with increasing hydrogen concentration for hydrogenated a-Ge samples.