Thermoelectric performance of tin and selenium co-doped bismuth telluride in the temperature range 10–300 K, prepared by solid-state reaction is reported in the current work. The powder X-ray diffraction study reveals hexagonal crystal structure with R3‾m space group. Energy dispersive X-ray analysis confirms elemental composition within the experimental limits and Field Emission Scanning Electron Microscopy (FESEM) shows uniform grain density and porosity on the surface of the pristine and doped samples. The electrical resistivity shows quasi degenerate semiconducting behavior and the temperature dependent Seebeck coefficient confirms n-type semiconducting nature of the pristine as well as doped samples. The carrier concentration and carrier mobility are of the order 1025/m3 and 10−4 m2/Vs respectively. A significant reduction in the thermal conductivity has been found in the (Bi0.98Sn0.02)2Te2.7Se0.3 compound, leading to an enhancement in the power factor (PF) and thermoelectric figure of merit (ZT) by 3.2 and 13.5 times respectively as compared to that of the pristine sample Bi2Te3 at 300 K. The highest ZT value of about 0.27 is achieved for (Bi0.98Sn0.02)2Te2.7Se0.3 at 300 K.
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering