Optimization of thermoelectric properties in elemental tellurium via high pressure

Abstract

High pressure and high temperature (HPHT) technology, as an extreme physical condition, plays an important role in regulating the properties of materials, having the advantages of enhancing doping efficiency, refining grain size, and manufacturing defects, therefore it is quite necessary to study the effectiveness on tuning thermoelectric properties. Elemental telluride, a potential candidate for thermoelectric materials, has the poor doping efficiency and high resistivity, which become an obstacle for practical applications. Here, we report the realization of a dual optimization of electrical behaviors and thermal conductivity through HPHT method combining with the introduction of black phosphorus. The results show the maximum zT of 0.65 and an average zT of 0.42 (300 K–610 K), which are increased by 55% and 68% in the synthesis pressure regulation system, respectively. This study clarifies that the HPHT method has significant advantages in modulating the thermoelectric parameters, providing a reference for seeking high performance thermoelectric materials.