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This paper presents an overview and analysis of our earlier obtained experimental results on the dependences of kinetic properties of single PbSe quantum wells and PbSe-based superlattices on the PbSe layer thickness d. The observed oscillatory character of these dependences is attributed to quantum size effects due to electron or hole confinement in quantum wells. Some general regularities and factors that determine the character of these quantum size effects are established. The influence of the oxidation processes and doping on the d-dependences of the transport properties is revealed. A periodic change in the conductivity type related to quantum size oscillations is detected. It is shown that the experimentally determined values of the oscillation period Dd are in good agreement with the results of theoretical calculations based on the model of a rectangular quantum well with infinitely high walls, taking into account the dependence of the Fermi energy e F on d and the availability of subbands below e F . It is established that the Dd value for the superlattices is practically equal to the Dd value observed for the single PbSe thin film.

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The dependences of electrical conductivity, the Hall coefficient, the Seebeck coefficient, thermoelectric power factor and microhardness of Bi2Se3 polycrystals on the degree of deviation from stoichiometry 59.9-60.0 at. % Se and temperature (77-300 K) were obtained. The samples exhibited n-type conductivity in the studied ranges of compositions and temperatures. The boundaries of the Bi2Se3 homogeneity region were estimated. A non-monotonic behavior of the concentration dependences of the properties in the studied composition range, associated with a change in the phase composition and defect structure under the deviation from stoichiometry, was observed. The calculation of the power coefficient in the temperature dependence of electron mobility showed that in a stoichiometric Bi2Se3, electrons are predominantly scattered by acoustic phonons, and under the deviation from stoichiometry the contribution of impurity scattering increases. Based on the experimental data, the Fermi energy EF was calculated in the approximation of the relaxation time and within the framework of the single-band model with a quadratic dispersion law. The obtained values of EF showed that both in stoichiometric and non-stoichiometric Bi2Se3, the conduction is mainly due to electrons in the lower conduction subband.

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