Enhanced thermoelectric performance of In and Se co-doped GeTe compounds

GeTe-based alloys have been considered promising p-type thermoelectric materials at medium temperatures (300-800 K). Indium (In), an effective dopant that introduces resonant states, and selenium (Se), which reduces lattice thermal conductivity, were combined. The process resulted in the enhancement of the power factor because of the distortion of the density of state and descent of thermal conductivity after the appearance of point defects and the scattering of boundaries. Ge0.99In0.01Te0.95Te0.05 had a high zT of similar to 1.38, which is higher than the zT values of Inor Se-doped systems. The high zT demonstrated that p-type In/Se co-doped GeTe compounds exerted synergistic effects on electrical and thermal transport. (C) 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).