Rare earth chloride Compositing and multiscale structure lead to high thermoelectric performance in p-type Cu3SbSe4

Cu3SbSe4 is a promising Te-free p-type thermoelectric material, characterized by earth-abundant, low-cost, and environmentally friendly constituents. Nonetheless, its thermoelectric performance is poor due to its extremely low electrical conductivity (deriving from the low carrier concentration) and high lattice thermal conductivity. Herein, we report a high-performance Cu3SbSe4-based material by compositing LaCl3 and introducing multiscale structure. The LaCl3-composted Cu3SbSe4 forms heterojunctions that facilitate charge accumulation at the interfaces. The redistribution of electrons between the two materials increases the electrical conductivity without damaging the Seebeck coefficient, and thereby significantly improving the power factor to similar to 1150 mu Wm(-1)K(-2) for Cu3SbSe4-based bulk. Furthermore, the hierarchical architecture defects are induced by LaCl3 compositing, yielding a minimum kappa(lat) of similar to 0.68 Wm(-1)K(-1) at 673 K. As a consequence, a maximum ZT value of similar to 0.90 at 673 K is achieved in the Cu3SbSe4 +2 mol% LaCl3 sample, representing an 80 % improvement compared to the pristine Cu3SbSe4.