Realizing nearly isotropic thermoelectric properties in 2D-layered SnS nanomaterials through highly symmetric metastable-phase powder precursors

Metastable materials offer a broad and novel platform for the development of next-generation science and technology. Phase engineering including synthesis of materials with unconventional phases and phase transition of metastable materials has been explored in layered materials but has not tackled their anisotropy issue yet. The high anisotropy in layered materials further adds the cost of orientation screening of materials. Herein, we report the effect of Ag doping on facilitating the formation of metastable π-cubic phase SnS during the solvothermal synthesis process. On this basis, we construct cubic-to-orthorhombic (CTO) samples and elucidate the intrinsic mechanisms of its nearly isotropic thermoelectric properties by characterizing the texturing information and analyzing the valence charge density calculated by density functional theory (DFT). This work demonstrates a convenient approach to synthesize layered materials with isotropic electrical and thermal transport behaviors through a precursor of metastable phase.