Transport and thermoelectric performance of n-type PbTe films

Abstract

In the present work, a systematic study of structural, transport, and thermoelectric properties of n-PbTe films on a mica substrate has been carried out. A wide range of film samples with hole concentration from n = 8 × 1016 cm−3 to n = 3 × 1018 cm−3 were obtained by variation of composition of the stoichiometric PbTe and by additional doping with donor iodine impurity. Based on measurements obtained by the four coefficients method, the direct estimation of the density of states effective mass and the scattering mechanism of the investigated n-PbTe films has been carried out. The high thermoelectric figure of merit Z ≈ 1.3 × 10−3 K−1 at T = 300 K has been obtained. Such a high thermoelectric figure of merit Z for n-PbTe films opens a possibility for the fabrication of the Film Thermoelectric Modules (FTEM), which could be a candidate for application at micro-scale thermoelectric converters.