Because materials related to Bi2Te3 have the best ZT values at room temperature, some of our research involves looking for new small band gap semiconductors in tellurium-based systems. Since heavy atoms and large unit cells are good ways to keep the lattice thermal conductivity low, we focus primarily on ternary and quaternary tellurides containing heavy metals.
This research has resulted in the discovery of many new compounds, among them:
The electrical resistivity vs. temperature and the structure of Ni5.7SbTe2. The behavior of the resistivity indicates that this compound is metallic and therefore is unlikely to be a good thermoelectric. Indeed, the measured value of the thermopower is quite small.
T.K. Reynolds, J.G. Bales, and F.J. DiSalvo, Chem. Mater. 14, 4746 (2002).