Realizing n-type CdSb with promising thermoelectric performance

Realizing high performance in both n-type and p-type materials is essential for designing efficient ther-moelectric devices. However, the doping bottleneck is often encountered, i.e., only one type of conduction can be realized. As one example, p-type CdSb with high thermoelectric performance has been discovered for several decades, while its n-type counterpart has rarely been reported. In this work, the calculated band structure of CdSb demonstrates that the valley degeneracy is as large as ten for the conduction band, and it is only two for the valence band. Therefore, the n-type CdSb can potentially realize an ex-ceptional thermoelectric performance. Experimentally, the n-type conduction has been successfully real-ized by tuning the stoichiometry of CdSb. By further doping indium at the Cd site, an improved room -temperature electron concentration has been achieved. Band modeling predicts an optimal electron con-centration of similar to 2.0 x 10 19 cm -3, which is higher than the current experimental values. Therefore, future optimization of the n-type CdSb should mainly focus on identifying practical approaches to optimize the electron concentration.(c) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

Realizing high performance in both n-type and p-type materials is essential for designing efficient thermoelectric devices. However, the doping bottleneck is often encountered, i.e., only one type of conduction can be realized. In this work, the band structure of CdSb is calculated, revealing the potential of exceptional thermoelectric performance in n-type CdSb. Experimental results show successful realization of n-type conduction by tuning the stoichiometry of CdSb and further doping with indium. Future optimization of n-type CdSb should focus on identifying practical approaches to optimize the electron concentration.