Electronic structure engineering of IV-VI group semiconductors

Abstract

The IV-VI group semiconductors are important thermoelectric materials that exhibit promising energy conversion efficiencies. The thermoelectric figures of merit of IV-VI group semiconductors have been greatly enhanced in recent years via the engineering of electrical and thermal transport properties. In this presentation, I will speak about the doping effects of the pnictogen and halogen group elements on the electronic structures of tin selenide and the related IV-VI compounds based on density functional theory(DFT) computational results. Interesting doping effects such as resonant electronic states and charge delocalization in the cross-plane direction are predicted from DFT calculations. As the electrical transport properties strongly depend on the electronic structures, the Seebeck coefficients and normalized electrical conductivities of the doped systems are also computed using the Boltzmann transport equations. The theoretical results are expected to stimulate further experimental studies for the enhancements of thermoelectric energy conversion efficiencies of the IV-VI group semiconductors.