Synergistic modulation of power factor and thermal conductivity in Cu3SbSe4 towards high thermoelectric performance

In this study, we develop a synergistic modulation of the thermal conductivity and power factor of Cu 3 SbSe 4 -based materials through Sn and Zr or Hf co-doping by using a facile microwave-assisted solvothermal method. A series of Cu 3 Sb 1-x M x Se 4 (M = Zr or Hf, x = 0, 0.02, 0.04, 0.06 and 0.08) compounds are firstly synthesized through the microwave-assisted solvothermal method combined with spark plasma sintering (SPS) process. The effect of Zr and Hf doping on the thermoelectric properties of Cu 3 Sb 1-x M x Se 4 (M = Zr or Hf) has been investigated. With increasing the content of Hf and Zr, the thermal conductivity of Cu 3 Sb 1-x M x Se 4 (M = Zr or Hf) is obviously decreased to 0.518 Wm −1 K −1 of Cu 3 Sb 0.92 Hf 0.08 Se 4 and 0.433 Wm −1 K −1 of Cu 3 Sb 0.92 Zr 0.08 Se 4 at 623 K, respectively. In addition, Sn doping further improves the low electrical conductivity and boosts the power factor, yielding a peak zT value of ~0.82 of Cu 3 Sb 0.91 Sn 0.03 Hf 0.06 Se 4 at 623 K, which is ~228% higher than that of the pristine Cu 3 SbSe 4 . Our work provides a new methodology for the decoupling of thermal and electrical properties of the Cu 3 SbSe 4 -based thermoelectric materials .