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用熔融退火结合放电等离子烧结法制备了In0.3Co4Sb12-xSex(x=0—0.3)方钴矿热电材料,探讨了In的存在形式,系统研究了Se掺杂量对结构和热电性能的影响.结果表明:In可以填充到方钴矿二十面体空洞处,过量In在晶界处形成InSb第二相,Se对Sb的置换使晶格常数减小,In填充上限降低;In0.3Co4Sb12-xSex样品呈n型传导,随着Se掺杂量的增大,载流子浓度降低,电导率下降,Seebeck系数增大,功率因子有所降低;由于在结构中引入了质量波动及晶格畸变,适量的Se掺杂可以大幅降低材料晶格热导率;样品In0.3Co4Sb12和In0.3Co4Sb11.95Se0.05的最大ZT值均达到1.0以上.
The In0.3Co4Sb12-xSex (x = 0-0.3) cristobalite thermoelectric material was prepared by melt-annealing combined with spark plasma sintering. The existence of In was discussed. The influence of the amount of Se doping on the structure and thermoelectric properties was systematically studied. The results show that: In can fill the icosahedral icosahedral icosahedron, an excessive amount of In forms a second InSb phase in the grain boundary, the substitution of Se for Sb decreases the lattice constant, and the upper limit of the In filling decreases. In0.3Co4Sb12-xSex The sample is n-type conductivity, with the increase of Se doping amount, the carrier concentration decreases, the conductivity decreases, Seebeck coefficient increases, the power factor is reduced; due to the introduction of the structure quality fluctuations and lattice distortion, Appropriate amount of Se doping can significantly reduce the thermal conductivity of the material lattice; Sample In0.3Co4Sb12 and In0.3Co4Sb11.95Se0.05 maximum ZT value of 1.0 or more.