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 re...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∼2.0×1019 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.展开更多
基金supported by the Shenzhen Science and Tech-nology Program (No.KQTD20200820113045081)the State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology.J.M.acknowledges the financial support from the National Natural Science Foundation of China (No.52101248)+6 种基金Shenzhen fundamental research projects (No.JCYJ20210324132808020)the start-up funding of Shenzhen,and the start-up funding of Harbin Institute of Technology (Shenzhen).Q.Z.acknowledges the financial support from the National Nat-ural Science Foundation of China (Nos.52172194 and 51971081)the Natural Science Foundation for Distinguished Young Scholars of Guangdong Province of China (No.2020B1515020023)the Natural Science Foundation for Distinguished Young Scholars of Shenzhen (No.RCJC20210609103733073)the Key Project of Shenzhen Fundamental Research Projects (No.JCYJ20200109113418655)F.C.acknowledges the financial support from the National Natural Science Foundation of China (No.51871081)H.L.acknowledges the financial support from the National Natural Science Foundation of China (No.62174044).
文摘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∼2.0×1019 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.
