Enhancement in power factor due to anti-correlation between electrical conductivity and thermoelectric power and induced magnetic ordering in high mobility Zn doped Bi2Te3 topological insulator

Abstract

Electrical resistivity, thermoelectric power, magnetotransport and magnetization of Zn doped Bi2Te3 Topological Insulator were studied. Electrical conductivity is enhanced at higher Zn concentration, and the carrier mobility estimated from Hall data reaches a remarkable value of ∼7200 cm2 V-1S−1. Large positive magnetoresistance (MR∼400%) is observed in high mobility samples. Interestingly it is found that the coupling between electrical conductivity and Seebeck coefficient is broken for higher Zn doped Bi2Te3 samples which effectively enhances the thermoelectric power factor (from 2.1mW/K2m for Bi2Te3 to 4.64mW/K2m for Zn doped Bi2Te3).