SCATTERING MECHANISMS OF ELECTRONS IN ZNSE CRYSTALS WITH HIGH MOBILITY

In low‐ohmic n‐type ZnSe crystals with the room temperature specific resistance of (3 to 5) Ω cm and electron concentration from 3 × 1015 to 2 × 1016 cm−3 Hall‐effect, electrical conductivity, and charge carrier mobility is investigated in the temperature interval from 10 to 300 K. The basic parameters of the samples are determined. It is found from the experimental data that the mobility is higher than the theoretical value in the investigated temperature range. It is argued that in the region of ionized impurity scattering this descrepancy between theory and experiment is due to the inadequacy of known scattering based on the Born approximation, as for ZnSe this approximation is valid at T > 140 K, where the phonon scattering is predominant. To square the theory with the experiment in the phonon scattering region a polaron effect is taken into account, which manifests itself in renormalization of the carrier effective mass as well as in alteration of the mobility temperature dependence due to the effect of screening of the interaction with polar vibrations. The theoretical consideration of this question is given which allows to bring the theory and the experiment to a satisfactory correspondence. Copyright © 1979 WILEY‐VCH Verlag GmbH & Co. KGaA