Te-doped Cu2Se nanoplates with a high average thermoelectric figure of merit

Understanding the impact of dopants can direct the design of high-performance thermoelectric nanomaterials. In this study, we use Te as a dopant to modify Cu2Se nanoplates. It has been found that Te can be uniformly doped and distributed in the synthesized products to form Cu2Se1-xTex nanoplates with controlled Te content. Also, a phase transition from the original beta-phase Cu2Se nanoplates to a-phase Cu2Se1-xTex nanoplates was observed with increasing Te doping level. From the thermoelectric evaluation of the sintered pellets of Cu2Se1-xTex nanoplates, it was found that Te can effectively modify their thermoelectric properties, especially their electrical transport properties. Finally, a high average figure-of-merit value of similar to 1.2 in the temperature range from 400 K to 850 K was observed for the Cu2Se0.98Te0.02 sample