Herein, we investigated the influence of sulfur (S) addition on the phase formation behavior and thermoelectric transport properties of n-type Cu0.008Bi2Te3. A complete single phase of rhombohedral Bi2Te3 was formed in Cu0.008Bi2Te2.8S0.2, whereas a mixture of Bi2Te3 and Bi2Te2S1 phases was generated at higher S contents. We elucidated the complex effects of S substitution at Te-site on transport properties of Cu0.008Bi2Te3; (1) increase in density-of-states effective mass, (2) decrease in weighted mobility ratio, (3) reduction in lattice thermal conductivity, and (4) reduction in bipolar thermal conductivity. Despite the slight deterioration in electronic transport properties, a maximum thermoelectric figure of merit (zT) of 0.82 was achieved at 400 K in Cu0.008Bi2Te2.8S0.2 due to the synergetic effect of intensified point defect phonon scattering in a wide temperature range and suppressed bipolar thermal conduction at elevated temperatures.
|Number of pages||9|
|Journal||Journal of Materials Research and Technology|
|Publication status||Published - 2021 Nov 1|
Bibliographical noteFunding Information:
This work was supported by the Samsung Research Funding & Incubation Center of Samsung Electronics under Project Number SRFC-MA1701-05.
© 2021 The Author(s)
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Surfaces, Coatings and Films
- Metals and Alloys