I n low-ohmic n-type ZnSe crystals with the room temperature specific resistance of (3 t o 5) rZ cm and electron concentration from 3 x 10l6 to 2 x 10l6Hall-effect, electrical conductivity, and charge carrier mobility is investigated in the temperature interval from 10 t o 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 t o 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 t o the effect of screening of the interaction with polar vibrations. The theoretical consideration of this question is given which allows t o bring the theory and the experiment to a satisfactory correspondence.

No abstract

The transverse electric field E y which appears in lateral superlattices (SLs) in the presence of a high applied electric field E x and a low magnetic field H normal to the SL plane (H OZ) is calculated. When the electron energy spectrum is non-additive, the field E y contains both the Hall field and the spontaneous transverse electric field which exists without H. The field E y is a multiple-valued and sign-changing function of E x . The kinetic potential whose minimum corresponds to the stationary state of the non-equilibrium electron gas is used. The magnetoresistance caused by the appearance of a spontaneous transverse EMF is investigated.

No abstract

No abstract

The ac absorption constant of an inhomogeneous semiconductor is calculated without any assumptions of electron density fluctuations to be small. A generalized Herring's method is used for calculating the effective conductivity. The method leads to a closed formula in the case of a heterogeneous two-phase system. The presence of a maximum in the frequency dependence of absorption is explained and its connection with the system parameters is determined.

The light-o r radioelectrical effect (RE) (photon drag) in isotropic semiconductors with parabolic conduction band is longitudinal /l/. It is connected, as known, with the fact that with the propagation electromagnetic waves (EMW) free c a r r i e r s absorb both energy and E M W momentum, thereby electrons a r e generated with directed motion, and in this direction a constant voltage arises under open circuit conditions /2 to 7/. At the same time a transverse RE is possible under anisotropic conditions. The effect consists in the appearance of a dc voltage, normal to the light propagation. This can be caused by a manyvalley conduction band /8, 9/ o r by the non-sphericity of the isoenergetical surfaces /9, lo/.In the present note we show that the transverse RE can also take place when the anisotropy of optical properties is induced by polarized laser radiation in an isotropic medium. It is known that intensive EMW may influence the kinetic effects in semiconductors, changing 1) the probability of electron scattering by phonons o r impurities, 2 ) the electron temperature, 3) the carrier concentration in the band (see review /11/), Here we consider only the first factor, which, as will be shown below, is a sufficient condition for the existence of transverse RE. It should be noted that a large number of publications a r e devoted lately to the same photostimulated effects (especially in recent time) /12 to 17/.We examine the system "current c a r r i e r s + scatterers", which is placed i n a linearly polarized EMW field (z(t) = 3 cos wt; $(t) = [i'. g(t)] ) of classical frequency w ( w <(E ; E is an average c a r r i e r energy, h = 1), in a dc electric field Eo and in a strong radiation field $(t) = I ? s i n Q t , which is considered to be a linearly polarized hf field: QT >> 1 ( z is the characteristic relaxation

Calculations are given of the conductivity tensor otJ for semiconductor structures with one-dimensional superlattice taking into account the interaction of electrons of one minizone with acoustic vibrations and impurities. Kubo-Mannary method is used, which allows to leave the limits of the Boltzmann kinetic equation. The dependence of otj on the SL parameters is obtained. ITpOBeneH paCYeT TeH3Opa 3 J I~H T~O l l~O B O~H O C T~