Economical Preparation of Nanostructured Bulk (BixSb1-X)2Te3 Thermoelectrics

Thermoelectric technology is becoming one of the important elements in sustainable energy due to its capability in green conversion of waste heat into electricity. Solid solution alloys based on Bi₂Te₃ have been some of the most efficient thermoelectric materials near the room temperature for many years. Recently there have been advances in the thermoelectric efficiency of (Bi_xSb_1-x)₂Te₃ alloy via bulk nanostructuring. The fabrication process of the alloy from elements of Bi, Sb, and Te often involves mechanical alloying with extensive milling time. This process is slow and consumes significant electric power. Here we report and compare three different methods to prepare powders of Bi₂Te₃ and Sb₂Te₃ binary alloys and (Bi_xSb_1-x)₂Te₃ ternary alloys: conventional high energy mechanical milling and two alternative methods namely induction melting and thermomechanical method.. In all three methods the obtained powders are single phase and possess good homogeneity. Efficiency and advantages of different methods have been discussed. Alternative techniques introduced in this work provide a more efficient approach with higher yield for large scale preparation of (Bi_xSb_1-x)₂Te₃ thermoelectric structures.