TRANSPORT-PROPERTIES OF FLASH-EVAPORATED (BI1-XSBX)2TE3 FILMS .2. THEORETICAL-ANALYSIS

An analysis of the temperature dependence of several transport properties, particularly the Seebeck and Hall coefficients, of thermoelectrically optimized p-type (Bi1 - xSbx)2Te3 films is carried out in the interval from 80 to 350 K for x = 0.75 including a comparison with bulk material data. The model calculations are based on the solution of the homogeneous Boltzmann equation in a relaxation time approximation since the films exhibit an in some ways bulk-like behaviour, e.g. the Hall mobility is of the order of that of the bulk material. In the framework of a one-valence-band model, the analysis of both bulk and film data favours a non-parabolic dispersion relation for Bi0.5Sb1.5Te3. It is shown that acoustic intravalley scattering is the predominant scattering mechanism of the charge carriers in the thermoelectrically optimized films. © 1990.