Two-band conduction in electron-irradiated n-InSe single crystals

The electrical properties of n-InSe single crystals irradiated with 9.2-MeV electrons are investigated in the temperature range 80-400 K. The observed extrema in the temperature dependences of the Hall coefficient and the electron mobility are explained by assuming the existence of mixed conduction with the carriers in the 3D conduction band and 2D electron gas. The numerical calculations were carried out by taking into account a redistribution of the carriers between the conduction band and the states of a 2D electron gas and well reproduce the experimental data. A numerical analysis of the temperature dependences of the concentration of 3D electrons within the single donor-single acceptor model and that of the Fermi-level temperature dependences have shown that n-InSe irradiated with high-energy electrons is highly compensated (N-A/N-D = 0.988-0.998) with a concentration of the donors N-D = (0.69-1.2) x 10(17) cm(-3) and the activation energy of three-dimensional conduction is 93-139 meV. (C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim