Enhanced thermoelectric properties of hydrothermally synthesized n-type Se&Lu-codoped Bi 2 Te 3

N-type Se&Lu-codoped Bi 2 Te 3 nanopowders were prepared by hydrothermal method and sintered by spark plasma sintering technology to form dense samples. By further doping Se element into Lu-doped Bi 2 Te 3 samples, the thickness of the nanosheets has the tendency to become thinner. The electrical conductivity of Lu 0.1 Bi 1.9 Te 3− x Se x material is reduced with the increasing Se content due to the reduced carrier concentration, while the Seeback coefficient values are enhanced. The lattice thermal conductivity of the Lu 0.1 Bi 1.9 Te 3− x Se x is greatly reduced due to the introduced point defects and atomic mass fluctuation. Finally, the Lu 0.1 Bi 1.9 Te 2.7 Se 0.3 sample obtained a maximum ZT value of 0.85 at 420 K. This study provides a low-cost and simple low-temperature method to mass production of Se&Lu-codoped Bi 2 Te 3 with high thermoelectric performance for practical applications.