Simultaneous regulation of electrical and thermal transport properties in CuInTe2 by directly incorporating excess ZnX (X=S, Se)

Abstract

Developing high thermoelectric performance CuInTe2 based materials is technologically and environmentally intriguing, in order to achieve this, nanoscale heterostructure barrier blocking is proposed and adopted in this work by directly incorporating excess ZnX (X=S, Se) to regulate the electrical and thermal transport properties of CuInTe2. The results prove that part of the ZnX dissolves into the CuInTe2 matrix during the hot press process while the residual ZnX acts as a nanoscale heterostructure barrier blocking for both the hole and phonon. As a consequence, three thermoelectric parameters of the CuInTe2 have been optimized simultaneously by this approach, owing to the formation of Zn- In point defects to improve carrier concentration, the concurrent hindering to the minority carriers resulting from the energy level difference between matrix and nano-heterostructure to enhance the Seebeck coefficient, and intensive phonon scattering by the nanoscale heterostructure barrier blocking to reduce the thermal conductivity. Eventually, a 90% enhanced ZT value of 1.52 has been obtained in the 6wt% ZnS added CuInTe2 sample.