Room Temperature Thermoelectric Properties of Isostructural Selenides Ta2PdS6 and Ta2PdSe6

We have measured thermoelectric properties of Ta2PdX6 (X=S, Se) around room temperature using single crystal samples. We find that the power factor of Ta2PdX6 is relatively high from middle-low to room temperatures, and notably Ta2PdSe6 shows the largest power factor among thermoelectric materials with an electrical conductivity of 10-2 {Omega}cm at 300 K. Ta2PdS6 will be a possible candidate for a Peltier cooling material if the lattice thermal conductivity is reduced by chemical substitution.