Epa Analysis of Frequency Dependent Loss Data For a-Ge and a-Si

Abstract

There have recently been several improvements of ac Hop** conductivity theory. Movaghar and co-workers ^1,2 Develop a rndom walk model. In the “extended pair approximation” Summerfield and Butcher^3,4 analyse the Miller Abrahams equivalent circuit⁵ to take into account the effect of neighbouring sites on the response of a particular pair of sites. In this paper we examine recent data for sputtered filmsof a-Ge^6,7 and a-Si (previously unpublished) in the light of the EPA g and the recent observation by Summerfield that it is the network aspect of the conductivity problem which controls the frequency dependence through a universal curve.