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

Abstract 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 ⿼1.38, which is higher than the zT values of In- or Se-doped systems. The high zT demonstrated that p-type In/Se co-doped GeTe compounds exerted synergistic effects on electrical and thermal transport.