Microstructure and thermoelectric properties of chlorine-filled CoSb3 skutterudites synthesized by HPHT process
Microstructure and thermoelectric properties of chlorine-filled CoSb3 skutterudites synthesized by HPHT process
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DOI：
10.1016/j.ceramint.2021.10.219
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发表时间：
2021-10
影响因子：
5.2
通讯作者：
Chenyang Xiao;Jialiang Li;Bo Duan;Houjiang Yang;Hongtao Wang;Ling Zhou;Guodong Li;P. Zhai
中科院分区：
文献类型：
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作者：
Chenyang Xiao;Jialiang Li;Bo Duan;Houjiang Yang;Hongtao Wang;Ling Zhou;Guodong Li;P. Zhai
填充CoSb3基方锰矿是一种很有前途的中温热电材料。然而，含有正电性填充物的p型Skutterudite需要通过在骨架上掺杂原子来进行额外的电荷补偿，这导致了增强的载流子散射。本工作采用高压高温(HPHT)工艺，成功地制备了电负性客体氯填充CoSb3材料。在没有电荷补偿的情况下，可获得高达∼23%的空位氯填充分数。氯离子填充剂表现出p型电子受体行为，可以将原始CoSb3的空穴浓度提高到1019 cm−3数量级。随着氯离子含量的增加，填充氯离子的方铅矿出现了异常的脊椎形态和细小的纳米颗粒。在室温下，由于点缺陷、响尾声和晶界的散射增强，Cl0.6Co4Sb12样品的晶格热导率比原始CoSb3样品显著降低46%。综上所述，HPHT工艺很有希望使用氯作为额外的p型掺杂候选者来产生显著增强的声子散射。
Filled CoSb3-based skutterudites are promising middle-temperature thermoelectric materials. However, p-type skutterudites containing electropositive fillers require additional charge compensation by doping atoms at the framework, which leads to enhanced carrier scattering. In this work, p-type filled CoSb3materials with electronegative guest Cl were successfully prepared by high-pressure high-temperature (HPHT) process. A high filling fraction of Cl in void sites reaching ∼23% was obtained without charge compensation. Cl filler exhibited p-type electron acceptor behavior and can increase hole concentration of pristine CoSb3to a magnitude of 1019cm−3. As the content of Cl rose, abnormal spinal morphology and fine nano grain were observed in Cl-filled skutterudites. In turn, lattice thermal conductivity of Cl0.6Co4Sb12sample significantly reduced by 46% when compared to pristine CoSb3at room temperature due to enhanced scattering of point defect, rattler, and grain boundary. In sum, HPHT process looks promising for using Cl as additional p-type dopant candidate to yield significantly enhanced phonon scattering.