Закономерности поведения температурных зависимостей удельного сопротивления кристаллов твердых растворов (Bi-=SUB=-2-x-=/SUB=-Sb-=SUB=-x-=/SUB=-)Te-=SUB=-3-=/SUB=- (0<x<2)

Abstract

It is shown that the change in the resistivity of crystals of solid solutions (Bi2-xSbx)Te3 (0<x<2) p-type in the temperature range preceding the onset of intrinsic conductivity is due not only to a change in the static relaxation time, the behavior of which in the temperature range from 80 to 300 K is determined mainly by the scattering of carriers on oscillations crystal lattice, but also by changing the concentration of light holes. The latter is a consequence of the transition of charge carriers from the subzone of heavy holes to the subzone of light holes, as a result of which the concentration of light holes, which make the main contribution to electrical conductivity, decreases with increasing temperature. As a consequence, the plasmon energy proportional to the concentration of charge carriers also decreases with increasing temperature, and the energy of this transition, comparable to the plasmon energy, increases. In this regard, crystals (Bi2-xSbx)Te3 have a specific feature due to the convergence of the plasmon energy and the interband transition, which creates conditions for increasing the intensity of the electron-plasmon interaction. Keywords: thermoelectric materials, bismuth and antimony tellurides, resistivity, interband transitions, plasma of free charge carriers.