Structural features and thermoelectric performance of Sb‐ and Bi‐doped Cu <sub>2</sub> SnSe <sub>3</sub> compounds
Shuping Deng, Xianyan Jiang, Lili Chen, Zi-Ye Zhang, N. D. Qi, Yichu Wu, Xinfeng Tang, Zhiquan Chen
Abstract
Abstract In this paper, a series of Sb‐doped and Bi‐doped Cu 2 Sn 1‐ x M x Se 3 samples (M = Sb, Bi) are prepared by vacuum melting combined with the spark plasma sintering process. The effects of different atomic doping amounts on their properties are discussed. Structural studies indicate that all obtained samples comprise a single Cu 2 SnSe 3 phase. Sb and Bi atoms are experimentally demonstrated to be efficient cation dopants for increasing the transport performance. Compared with that doping on the cation site, Bi doping is much more efficient in increasing the electron concentration of the Cu 2 SnSe 3 system. Ultimately, a high figure of merit of 0.36 is achieved in the Cu 2 Sn 0.94 Sb 0.06 Se 3 sample at 773 K due to the enhanced power factor and lowered lattice thermal conductivity, which are 1.73 times higher than those of the pure sample. Our results provide an efficient approach to enhance thermoelectric performance via other doping atoms, which could also be applied to copper‐based chalcogenide materials.