Advancing Carriers Mobility in MnSb<sub>2</sub>Te<sub>4</sub> Thermoelectrics via Tailored Textures and Vacancy Modification
Xiao Xu, Dasha Mao, Maciej Oskar Liedke, Maik Butterling, Juan Cui, Jinghan Wang, Yiyuan Luo, Zhen‐Hua Ge, Eric Hirschmann, A. Wagner, Jiaqing He, Kornelius Nielsch, Ran He
Abstract
Abstract Enhancing carrier mobility plays a crucial role in significantly improving thermoelectric performance. However, due to the lack of a systematic strategy, achieving high mobility remains an elusive goal for most compounds. In this study, the hot‐forging method is applied to polycrystalline MnSb₂Te₄, achieving a remarkable 300% improvement in carrier mobility. Through electron backscattering diffraction microstructural analysis, it is demonstrated how optimizing textures can accelerate carrier movement in MnSb₂Te₄ bulk materials. Moreover, theoretical calculations, combined with experimental positron annihilation spectroscopy, reveal that Te vacancies help counteract intrinsic cation defects, leading to a simultaneous increase in carrier mobility. As a result, the hot‐forged MnSb₂Te₄ specimen, with a diameter of 15 mm, reaches a record‐high maximum figure of merit ( ZT ) value of 1.3 at 773 K and an impressive average ZT of 0.7 between 323 and 773 K. The experimental output efficiency of 4.6%, observed at 773 K on the MnSb₂Te₄‐based single‐leg module, further confirms that the improved transport properties are due to the enhanced carrier mobility. This comprehensive study offers valuable insights into mobility enhancement in MnSb₂Te₄ and provides a promising direction for exploring similar improvements in other thermoelectric materials.