Detailed Theoretical Investigation and Comparison of the Thermal Conductivities of n- and p-type Bi2Te3 Based Alloys

Abstract

ABSTRACTIn this work we present a detailed theoretical investigation of the thermal conductivities of n-type 0.1 wt.% CuBr doped 85% Bi2Te3 - 15% Bi2Se3 and p-type 3 wt% Te doped 20% Bi2Te3 - %80 Sb2Te3 single crystals. The thermal conductivity contributions arising from carriers, electron-hole pairs and phonons are computed rigorously in the temperature range $300\,{\rm{K}}\, \le \,T\, \le \,500\,{\rm{K}}$. In agreement with available experimental measurements we theoretically find that the lowest total thermal conductivity is 3.15 W K−1 m−1 at 380 K for the n-type alloy and 1.145 W K−1 m−1 at 400 K for the p-type alloy. Stronger mass-defect scattering is found to be responsible for the lower thermal conductivity of the p-type alloy throughout the temperature range of the study.