Enhanced thermoelectric figure of merit in p-type BiSbTeSe alloy with ZnSb addition

We have prepared p-type BiSbTeSe alloys with different ratios of ZnSb addition by a zone melting method. The microstructure characterization shows that a second phase of ZnSeTe was generated in the matrix. Due to the ZnSb addition, the carrier concentration was increased, thus improving the electrical performance (power factor, alpha(2)sigma), while the lattice thermal conductivity (kappa(L)) was simultaneously decreased, mainly due to the introduced defects, such as anti-site substitution, the second phase and interfaces with different scales. As a result, a significant improvement in the thermoelectric figure of merit ZT was obtained, especially above 370 K, which is very beneficial for commercial applications in power generation.