Synergistic optimizing thermoelectric performance of SnTe by the integrated Multi-strategy

SnTe has been regarded as a Lead-free substitution for the outstanding thermoelectrics PbTe, owing to their similar crystal and band structures. However, the performance of pristine SnTe is limited by its intrinsic high carrier concentration, high thermal conductivity and low Seebeck coefficient. In this work, the integrated multistrategy, including band convergence, defect engineering and carrier manipulation, is applied to optimize the overall thermoelectric properties of SnTe. In practice, Cd-doping, Cu2Se nano-precipitate, and Sb-doping are introduced step by step to achieve the goals. Owing to the high efficiency of Cd-doping for band convergence and Cu2Se nano-precipitate for defect engineering, the obtained compounds exhibit the high carrier mobility, about 50 cm2 V-1 s- 1. Finally, a high peak ZT of 1.52 at 833 K is achieved in (Sn0.86Cd0.04Sb0.1Te)0.96(Cu2Se)0.04, accompanied with a low thermal conductivity of 1.3 W m- 1 K-1.