PREPARATION AND THERMOELECTRIC PROPERTIES OF Bi2Te(3-x)Sex SAMPLES BY HIGH-ENERGY BALL MILLING AND SPARK PLASMA SINTERING METHOD

Thermoelectric (TE) materials are environmentally friendly materials used in electrical conductivity and heat conversion processes. Bismuth telluride (Bi₂Te₃)-based TE materials are relatively maturity near low temperatures. Bismuth telluride-based TE material samples (Bi₂Te_(3-x)Se_x) with different Se doping ratios were prepared by high-energy ball milling (HEBM) and spark plasma sintering (SPS) methods. We investigated the effects of different doping ratios on the performance of the samples and found that the grain sizes in the samples obtained by the combined HEBM-SPS method were small with no obvious preference orientation. The TE properties of the Bi₂Te_(3-x)Se_x samples displayed obvious regularity with an increase in the Se doping amount. The ZT value of the sample was 0.62 when the doping amount was 0.6.