High thermoelectric performance of fullerene doped Bi0.5Sb1.5Te3 alloys

•A high thermoelectric ZT 1.47 ± 0.07 (at 358 K) of Bi0.5Sb1.5Te3 bulk alloys was achieved by incorporation of small amount of C60.•The C60 doped Bi0.5Sb1.5Te3 bulk alloys have the potential as high performance thermoelectric materials near room temperature.•The thermal conductivity was dramatically reduced to 0.4 W/(mK) at 358 K after C60 doping.

In this paper, we report our recent experimental findings on the enhancement of thermoelectric performance of C60 doped Bi0.5Sb1.5Te3 bulk alloys. Incorporation of a small amount of C60 significantly reduces the crystalline particle size and leads to closely packed nanostructure, whilst slightly improve the electric conductivity in the measured temperature range. In addition, a minimum thermal conductivity of 0.4 W/(mK) at 358 K was observed, which is identified to be caused by the strong lattice phonon scattering at grain boundaries, yielding a high figure-of-merit ZT = 1.47 ± 0.07 at 358 K. Our results demonstrate that the materials can be used for the development of advanced thermoelectrics.