| Abstract Scope |
Control of carrier concentration and thermal transport is crucial for realizing high-performance thermoelectric materials. In this talk, I will present the large modulation of carrier and phonon transport properties in layered SnSe induced by isovalent ion substitution. I will show that isovalent Te substitution at Se site significantly enhances electronic conductivity, with three-order-of-magnitude increase in hole concentration, and effectively reduces lattice thermal conductivity to less than one-third of its original value (Adv. Sci. 9, 2105958 (2022)). The large-size Te in Sn(Se1-xTex) weakens Sn–Te bonds, leading to high-density formation of hole-donating Sn vacancies, reduced phonon frequencies, and enhanced phonon scattering. Furthermore, I will show that Pb substitution at Sn site induces a structural phase transition from two-dimensional layered to three-dimensional cubic structure (Sci. Adv. 7, eabf2725 (2021)), resulting in substantial modulation of both electrical and thermal transport by temperature. |