Strain‐Mediated Lattice Rotation Design for Enhancing Thermoelectric Performance in Bi<sub>2</sub>S<sub>2</sub>Se
Adil Mansoor, Bushra Jabar, Fu Li, Sidra Jamil, Muhammad Fasehullah, Yuexing Chen, Guangxing Liang, Ping Fan, Zhuanghao Zheng
Abstract
Abstract A unique strain‐mediated lattice rotation strategy is introduced via nanocompositing to upsurge the optimized limits in the composition‐to‐structural pathway on rationally engineering the efficient thermoelectric material. In this study, a special lattice rotation via strain engineering is realized to optimize the desired electronic and chemical environment for enhancing thermoelectric properties in n ‐type Bi 2 S 2 Se. This approach results in a unique transport phenomenon to assist high‐energy electrons in transferring through the optimized transport channels, and appropriate structure disparity to significantly localize phonons. As a result, Sb over Cl doping in Bi 2 S 2 Se gently reduces E g and introduces defect states in bandgap with shifting down the Fermi level, thus causing increase in carrier concentration, which contributes to a higher power factor of ≈7.18 µW cm −1 K −2 (at T = 773 K). Besides, a lower thermal conductivity of ≈0.49 W m −1 K −1 is driven through lattice strain and defect engineering. Consequently, an ultra‐high ZT max = 1.13 (at T = 773 K) and a high ZT ave = 0.54 (323 K‐773 K) are realized. This study not only leads to an extraordinary thermoelectric performance but also reveals a unique paradigm for electron transportation and phonon localization via lattice strain engineering.