Dual-optimization of transport properties enabled by high-pressure treatments for CuInTe2 thermoelectric materials

Abstract

CuInTe2 is the focus of much research interest in I-III-VI2 diamondoid compounds due to its potentially high thermoelectric performance. However, its unmatched transport behaviors among electrical and thermal properties seriously impede enhanced thermoelectric performance. In this work, we demonstrate that high pressure can dual-optimize the electrical and thermal transport properties, leading to enhanced thermoelectric performance in CuInTe2 with cationic defects. The results indicate that the carrier concentration level is increased while greatly enhancing carrier mobility owing to the influence of high pressure on the band and electronic structures, realizing an excellent power factor of 1406 μWm−1K−2. Furthermore, high-pressure treatments and cationic defects can introduce multiple defect structures with various sizes, strongly scattering full-frequency phonons to reduce lattice thermal conductivity. With these great merits enabled by high pressure, the thermoelectric performance of CuInTe2 with cationic defects is improved and a maximum zT of 1.12 is obtained at 773 K, fully verifying the advantages of high-pressure treatments in terms of improving transport properties.