Acoustoelectric Current Saturation on Trigonal Se and Se _X Te_1-X Single Crystals

Abstract

In piezoelectric semiconductors like trigonal Se and Se_xTe_1-x single crystals the carrier mobility can be deduced from acoustoelectric current saturation (1) experiments. Measurements of the hole mobility in illuminated samples of trigonal Se from acoustoelectric current saturation were already performed by MORT (2). These experiments, however, yield no information about the influence of conductivity inhomogeneities, which are known to influence the transport properties of trigonal Se (3). The current voltage characteristics in Fig.1, measured for a vapour grown sample, exhibit a linear part for high illumination intensities prior to the onset of current saturation. This linear part is no longer present at lower light intensity. In the latter case the saturation onset is much less pronounced indicating a higher degree of inhomoge-neity of the sample.