Thermoelectric performance of Te doped with As and alloyed with Se

Abstract

Recently, it was found that element semiconductor tellurium (Te) behaved a high thermoelectric (TE) performance. Further enhancement of its TE performance was expected in decreasing phonon thermal conductivity. In this paper, element semiconductor Te doped with arsenic (As) and alloyed with selenium (Se) was prepared by one-step high-pressure method. Trace amounts of As doping could increase the carrier concentration of Te effectively and thereby optimize its power factor. The phonon thermal conductivity of Te was depressed sharply, due to the effect of high-pressure compression (introducing dislocations, lattice curvatures and nanograins) and Se alloying (introducing point defects and crystal dislocation). The beneficial effect of As doping on the power factor, high-pressure compression and Se alloying on thermal conductivity led to a peak ZT of 0.81 at 540 K for Te doped with 0.5 mol% As and alloyed with 10 mol% Se.