Influence of the behavior of charge carriers on the thermoelectric properties of PbTe:Bi thin films

Abstract

The influence of technological factors of thin film deposition by the method of open evaporation in vacuum on the realization of charge carrier scattering processes is investigated. The contribution to the transport phenomena of carrier scattering for PbTe:Bi films deposited on the muscovite mica and glass ceramic (sitall) (0001) substrates are determined. In particular, the surface-bound carriers (Fuchs and Sondheimer theory) and grain boundaries (Meijdes and Shatskis theory) are analyzed. The choice of the type of substrate material and the temperature modes of the deposition changed the structure of the film surface and, accordingly, the values of thermoelectric parameters of the initial material. In particular, the selection of experimental modes allows manipulating the grain size and the thickness of the film. Glass ceramic (sitall) substrates contribute to a significantly smaller grain size compared with the use of mica substrates. It is shown that the effects of grain boundaries scattering are dominant for all films. The surface effects are only significant for sufficiently thin films the thickness of which is commensurate with the mean free path of charge carriers.