Thermoelectric Properties of Off-Stoichiometric Bi 2 Te 2 Se Compounds

We report the thermoelectric characterization of off-stoichiometric Bi2Te2Se compounds fabricated with high energy ball milling followed by spark plasma sintering. Among the investigated off-stoichiometric Bi2Te2Se compounds, Bi2Te1.95Se1.05 showed a peak ZT of 0.76 at 523 K. We observed the scattering mode change in Bi2Te1.95Se1.05 compounds. From our results, the off-stoichiometric Bi2Te2Se compounds can be applied as n-type material for power generation at elevated temperature.