Effect of the Composition on the Dielectric Properties and Charge Transfer in 2D GaS1 –хSeх Materials

Abstract

The effect of the composition of the GaS–GaSe layered solid solutions on their dielectric characteristics and ac conductivity in the frequency band of 5 × 10⁴ to 3.5 × 10⁷ Hz is investigated. It is shown that with an increase in the selenium content in the GaS_{1 –х}Se_х single crystals the real and imaginary parts of the complex permittivity, dissipation factor, and ac conductivity grow significantly. The experimentally observed decrease in the permittivity of the investigated solid solutions with an increase in the frequency from 5 × 10⁴ to 3.5 × 10⁷ Hz is attributed to the relaxation dispersion. The nature of dielectric loss (reach-through conductivity loss) in the GaS_{1 –х}Se_х single crystals and the hopping mechanism of charge transfer over the states localized at the Fermi level are established. The main parameters of the localized states in the GaS_{1 –х}Se_х band gap are estimated.