Enhancing Carrier Mobility and Seebeck Coefficient by Modifying Scattering Factor

Thermoelectric materials possess the potential for refrigeration and power generation due to their ability to directly convert heat and electricity. Carrier mobility and the Seebeck coefficient are key properties of thermoelectric materials. Improving the effective mass is the most effective and frequent way to optimize the Seebeck coefficient. However, carrier mobility deteriorates dramatically with increasing effective mass and thus limits further improvement of thermoelectric performance. Here, the focus is on the importance of modifying the scattering factor (r) to enhance the electrical properties, and it is found that the anisotropic scattering factor enhances the carrier mobility and Seebeck coefficient of anion-doped n-type tin selenide crystals along the out-of-plane direction, indicating the potential of modifying r to improve electrical properties. Following this strategy, the average dimensionless figure of merit (ZT(ave)) for iodine-doped SnSe crystals is significantly improved from 0.84 to 1.57 in 300-773 K. The results emphasize the critical role of scattering factor and propose a new perspective for enhancing carrier mobility, providing a novel strategy to optimize thermoelectric performance.