摘要
It is known that p-type GeTe-based materials show excellent thermoelectric performance due to the favorable electronic band structure.However,n-type doping in GeTe is of challenge owing to the native Ge vacancies and high hole concentration of about 10^(21)cm^(-3).In the present work,the formation energy of cation vacancies of GeTe is increased through alloying PbSe,and further Bi-doping enables the change of carrier conduction from p-type to n-type.As a result,the n-type thermoelectric performance is obtained in GeTe-based materials.A peak zT of 0.34 at 525 K is obtained for(Ge_(0.6)Pb_(0.4))_(0.88)Bi_(0.12)Te_(0.6)Se_(0.4).These results highlight the realization of n-type doping in GeTe and pave the way for further optimization of the thermoelectric performance of n-type GeTe.
基金
Supported by the National Science Fund for Distinguished Young Scholars(Grant No.51725102)
the National Natural Science Foundation of China(Grant No.51861145305)。
