Thermoelectric transport properties and crystal growth of BiSbTe3 bulk materials produced by a unique high-pressure synthesis

Abstract

We report a significant enhancement in the figure of merit ZT of bulk BiSbTe₃ fabricated by high pressure sintering technique under variable pressures. High pressure intervention during synthesis processes can effectively adjust the thermoelectric transport properties and crystal structures of the reaction products. The novel vibration modes produced by high pressure in Raman spectra can induce a positive role in the reduction of thermal conductivity. Meanwhile, the electrical resistivity can also obtain an efficient decrease due to the effect of high pressure on the texture and the preferred orientation. Because of these positive effects, the maximum ZT has reached 1.4 at 432 K from synthesized BiSbTe₃ at 2.5 GPa in a short period. Therefore, we present that the appropriate high-pressure has a positive effect on the thermoelectric transport properties to produce the significant enhancement in thermoelectric properties of BiSbTe₃.