Realizing n-Type Ge Te through Suppressing the Formation of Cation Vacancies and Bi-Doping

【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 10²¹ 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_0.6Pb_0.4)_0.88Bi_0.12Te_0.6Se_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.更多还原

【Abstract】 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 10²¹ 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_0.6Pb_0.4)_0.88Bi_0.12Te_0.6Se_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.更多还原