High thermoelectric performance of (Bi_1‐xPr_x)₂(Te_0.9Se_0.1)₃ alloys prepared by high‐pressure sintering method

Abstract

In this article, n‐type (Bi1‐xPrx)2(Te0.9Se0.1)3 (x = 0, .002, .004, .008) alloys were fabricated by high‐pressure sintering (HPS) method together with annealing. The effect of high pressure and Pr contents on the microstructure and thermoelectric performance of samples were explored in detail. The results show that the HPS samples are composed of nanoparticles. Pr doping has significant impacts on the electrical and thermal transport properties of the Bi2Te2.7Se0.3 alloys. The HPS sample with x = .004 shows the maximum ZT value of .31 at 473 K, which is enhanced by 41% to compare with the Pr‐free sample. Annealing can improve the thermoelectric properties by increasing the electrical transport properties and decreasing the thermal conductivity simultaneously. As a result, the highest ZT value of 1.06 is achieved for the annealed sample with x = .004 at 373 K, which is beneficial to the thermoelectric power generation.