The n- and p-type thermoelectricity property of GeTe by first-principles study

Abstract

The electronic structure and thermoelectric property of GeTe are calculated by the First-principles calculations and Boltzmann transport theory. The deformation potential approximation and single parabolic band model are employed to compute the relaxation time. Owing to the accurate electronic structure calculated by Tran-Blaha modified Becke-Johnson (TB-mBJ) potential, the theoretical data (Seebeck coefficient, electrical conductivity and ZT) are in good agreement with experimental data. The thermoelectric property of n type is found to be significantly better than that of p type for temperature between 300 K and 800 K and carrier concentration between 1020cm−3 and 1022cm−3. For n type, the largest ZT value of 5.05 could be obtained at 2.5 × 1021cm−3 and 800 K, while for p type, the largest ZT value of 3.32 could be obtained at 7.0 × 1020cm−3 and 800 K. Our results give a valuable theoretical guidance for the high performance of GeTe through n doping.