Impurity band in electron-irradiated n-InSe

Abstract

Electrical properties of indium selenide InSe single crystals irradiated with electrons with energy of 9,2 MeV are investigated in the temperature range 80 to 400 K. The observed extrema in the temperature dependences of the Hall coefficient and the Hall mobility of electrons along the layers are explained by considering the two-band model with electrons in both the conduction and impurity bands created by donor centers. The carried out numerical calculations taking into account a redistribution of carriers between the bands well reproduce the experimental data. An analysis of the temperature dependence of chemical potential and calculations within the model of partially compensated donor level additionally confirm the existence of the impurity band with a width of 6 to 8 meV. High mobilities of the carriers in this band are supposed to be due to delocalized conduction type.