无机材料学报2023，Vol.38Issue(11)：1331-1337,中插12-中插13,9.DOI:10.15541/jim20230121
p型多晶Bi0.5Sb1.5Te3合金类施主效应与热电性能
Donor-like Effect and Thermoelectric Performance in p-Type Bi0.5Sb1.5Te3 Alloy
摘要
Abstract
Grain refinement is an effective way to improve the mechanical properties of Bi0.5Sb1.5Te3 based alloys.However,the donor-like effect caused by the grain refinement during powder metallurgy severely degrades the thermoelectric properties of the material,which limits the application of Bi0.5Sb1.5Te3-based alloys in micro thermoelectric devices.Therefore,in this study,focusing on p-type Bi0.5Sb1.5Te3-base alloy,the impact of grinding and desorption atmosphere on donor-like effect and thermoelectric transport properties of sintered samples during powder metallurgy process were systematically studied through experiments combined with theoretical calculations.Surface defects VTe..andVS'b'',generated by the grinding process of Bi0.5Sb1.5Te3-based alloy,reacts with the adsorbed O2 during sintering process.This generates a large number of VTe..vacancies and free electrons,leading to a donor-like effect and a significant decrease in carrier concentration.The use of protective atmosphere(Ar atmosphere)during grinding to avoid exposure to air or O2 desorption under protective atmosphere after grinding effectively suppresses the donor-like effect,maintaining high carrier concentration and electrical conductivity of the sample.Moreover,the performance is stable up to 473 K.The samples treated in air or sintered using powder placed in air exhibit a significant donor-like effect,and the carrier concentration decreases from 4.49×1019 cm-3 to 3.21×1019 cm-3.The maximum thermoelectric ZT of 1.03 is obtained at 402 K for the samples sintered with the powders treated under protective atmosphere,and the overall average ZTave reaches 0.92.This study provides a new avenue to regulate the donor-like effect of p-type polycrystalline Bi2Te3-based compounds and to optimize their thermoelectric properties.关键词
Bi0.5Sb1.5Te3合金/类施主效应/载流子浓度/热电性能Key words
Bi0.5Sb1.5Te3 alloy/donor-like effect/carrier concentration/thermoelectric property分类
化学化工引用本文复制引用
鲁志强,刘可可,李强,胡芹,冯利萍,张清杰,吴劲松,苏贤礼,唐新峰..p型多晶Bi0.5Sb1.5Te3合金类施主效应与热电性能[J].无机材料学报,2023,38(11):1331-1337,中插12-中插13,9.基金项目
国家自然科学基金(52122108,51972256) （52122108,51972256）
国家重点研发计划(2018YFB0703600) （2018YFB0703600）
湖北隆中实验室自主创新项目(2022ZZ-07)National Natural Science Foundation of China(52122108,51972256) （2022ZZ-07）
National Key Research and Development Program(2018YFB0703600) （2018YFB0703600）
Independent and Innovative Project of Longzhong Laboratory in Hubei Province(2022ZZ-07) （2022ZZ-07）
