Coexisting transport behaviors in quasibinary Cd((3-3m))Ga(2m)Te3 (m=0.75-0.98) system with structural vacancy and cationic interdiffusion

摘要

In Ga2Te3-rich quasibinary Cd(3 - 3m)Ga2mTe3 (m = 0.75-0.98) system there are two physical phenomena: structural vacancy (V) and its related cationic interdiffusion. The former is able to simultaneously govern the carrier, phonon transportations and the bandgap, while the latter merely facilitates the transportation of carrier to some extent. Accordingly, there are multiple transportation behaviors coexisting at a certain m value in this system. These behaviors, which have not only enhanced the carrier concentration (n), but have also increased the entropy of the lattice as m value increases, yield the highest thermoelectric figure of merit (ZT) of 0.55 at 682 K for m = 0.98. (C) 2015 Elsevier Ltd. All rights reserved.