The excellent TE performance of photoelectric material CdSe along with a study of Zn(Cd)Se and Zn(Cd)Te based on first-principles.

Abstract

Zn(Cd)Se and Zn(Cd)Te are well known for their excellent photoelectric performance, however, their thermoelectric (TE) properties are usually ignored. By taking advantage of first-principles calculations, the Boltzmann transport equation and semiclassical analysis, we executed a series of thermal and electronic transport investigations on these materials. Our results show that CdSe has the lowest anisotropic thermal conductivity, κL, of the four materials, at 4.70 W m−1 K−1 (c axis) and 3.85 W m−1 K−1 (a axis) at a temperature of 300 K. Inspired by the very low lattice conductivity, other thermoelectric parameters were calculated in the following research. At a temperature of 1200 K we obtained a pretty large power factor, S2σ, of 4.39 × 10−3 W m−1 K−2, and based it on the fact that the corresponding figure of merit ZT can reach 1.8 and 1.6 along the a axis and c axis, respectively. We revealed the neglected thermoelectric potential of CdSe by means of systematic studies and demonstrated that it is a promising material with both excellent photoelectric performance and thermoelectric performance.