Enhanced thermoelectric properties by Ir doping of PtSb2 with pyrite structure

The effects of Ir doping on the thermoelectric properties of Pt1–xIrxSb2 (x = 0, 0.01, 0.03, and 0.1) with pyrite structure were studied. Measurements of electrical resistivity ρ, Seebeck coefficient S, and thermal conductivity κ were conducted. The results showed an abrupt change from semiconducting behavior without Ir (x = 0) to metallic behavior at x = 0.01. The sample with x = 0.01 exhibited large S and low ρ, resulting in a maximum power factor (S2/ρ) of 43 μW/cmK2 at 400 K. The peculiar “pudding mold”-type electronic band dispersion could explain the enhanced thermoelectric properties in the metallic state.