Band convergence is a key strategy for enhancing thermoelectric (TE) performance. Herein, we demonstrate a promising approach to enhance band convergence through inducing Rashba splitting in topological insulators. Theoretically designed Janus β-Bi2Se2Te and β-Bi2Te2Se exhibited inherent topological band inversion and Rashba splitting due to the strong spin-orbit coupling (SOC) with broken inversion symmetry. These characteristics synergistically improve band convergence, leading to a substantially enhanced power factor. Meanwhile, the Janus structural asymmetry suppresses lattice thermal conductivity. Consequently, Janus structures achieve boosted TE performance, especially for β-Bi2Se2Te, peaking figure of merit (zT) of 2.82. This work establishes a new framework for designing Janus topological compounds with high TE performance by the synergistic effect of Rashba splitting and band inversion.
@article{arxiv.2506.21479,
title = {Synergy of Rashba and Topological Effects for High-Performance Bismuth-Based Thermoelectrics},
author = {Lei Peng and Ruixiao Lian and Hongyu Chen and Ben Li and Yu Wu and Yuxiang Zheng and Hao Zhang},
journal= {arXiv preprint arXiv:2506.21479},
year = {2025}
}