Determination of semiconductor energy gaps using the microwave cavity perturbation method

Abstract

A simple fitting procedure is described which helps to overcome the difficulties often encountered in extracting the complex dielectric constant epsilon using the cavity perturbation method for samples of irregular shape. The aim of this method is to determine the temperature dependence of the imaginary part of epsilon of a semiconductor with sufficient accuracy to give reliable values for its energy gap. The automatised experimental set-up used to verify the proposed method is presented and examples of application to germanium, silicon and to some new materials are given.