Effects of Bi2Te3 doping on the thermoelectric properties of Cu2Se alloys

Cu2Se and Bi2Te3 nano-powders prepared by the hydrothermal method were mixed and hot-pressed according to the molar ratio Cu2Se + x mol% Bi2Te3 (x = 0, 1, 2, 3). Bi2Te3 doping as the second phase can influence the microstructure of Cu2Se greatly, increase the carrier mobility and concentration, and reduce the resistivity significantly. The power factor increases by 17-42% compared with the pure sample. However, the total thermal conductivity increases further, which is not our expectation. Finally, the dimensionless thermoelectric figure of merit ZT is not well optimized.

Automated summary

The addition of Bi2Te3 as a second phase in Cu2Se thermoelectric material can greatly influence its microstructure, increase carrier mobility and concentration, and reduce resistivity. However, the total thermal conductivity increases further, which is not desired, and the optimization of the dimensionless thermoelectric figure of merit ZT is not achieved.