FRENKELS MECHANISM OF THERMOELECTRONIC IONIZATION IN SINGLE CRYSTALS OF GALLIUM SELENIDE

Measurements are made of the current‐voltage characteristics of monocrystalline GaSe specimens within the strong field region of up to 4 × 104 V/cm in the temperature range from 300 to 125 °K. The data obtained are discussed in terms of Frenkel's mechanism of thermoelectronic ionization documentclass{article}pagestyle{empty}begin{document}$(sigma = sigma _0 {rm e}^{beta sqrt E })$end{document}. The low field value for the activation energy of carriers, is found to be ΔE0 = 0.18 eV, and decreases with increasing electric field according to the formula ΔE = ΔE0 −2 documentclass{article}pagestyle{empty}begin{document}$ esqrt {e,E/varepsilon} $end{document} ab (e electronic charge, E electric field intensity, ϵ high‐frequency dielectric constant). Correlating the experimental data with Frenkel's theory, values of ϵ = 8 are obtained for gallium selenide. Copyright © 1969 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim