Температурная зависимость проводимости нитевидных кристаллов теллура

Abstract

In the temperature range 77−273K, a comparative analysis of the electrical conductivity of a whisker, an epitaxial film, and a single crystal of tellurium was undertaken. The electrical conductivity of the film and the single crystal increased monotonically up to 200K, then began to rise steeply, corresponding to thermal excitation of intrinsic carriers. The electrical conductivity of whiskers decreased with increasing temperature to 230K, after which it began to increase more gradually. It is assumed that in the case of tellurium whiskers, the classical size effect took place: the decrease in electrical conductivity was due to diffuse scattering of carriers by the lateral surface of the tellurium crystal and was intensified with increasing temperature. The uneven, tightly-convoluted surface of the samples was shown in images produced in a scanning electron microscope in the nanometer range.