Anisotropic thermoelectric properties of layered compound SnSe2

Similar to high performance SnSe thermoelectrics, SnSe2 is also a layered structured semiconductor. However, its anisotropic thermoelectric properties are less experimentally investigated. In this work, Cl-doped SnSe2 bulk materials are successfully prepared, and their thermal stability and anisotropic transport properties are systematically studied. Unexpectedly, different from the theoretical prediction and other typical layered thermoelectric compounds like Bi2Te3, the out-of-plane ZTc value is higher than in-plane ZTa for the same composition. The zT value is significantly enhanced by CI doping. A maximum ZTc of -0.4 at 673 K is achieved in SnSe1.88Cl0.12, twice higher than previously reported Cl-doped SnSe2 synthesized by the solvothermal method.