Control of donor-like effect in V2VI3 polycrystalline thermoelectric materials
Control of donor-like effect in V2VI3 polycrystalline thermoelectric materials
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V2VI3多晶热电材料中类施主效应的控制
DOI：
10.1016/j.materresbull.2017.11.025
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发表时间：
2018
影响因子：
5.4
通讯作者：
Zeng Xierong
中科院分区：
文献类型：
--
作者：
Hu Lipeng;Guo Yangming;Li Junqin;Ao Weiqin;Liu Fusheng;Zhang Chaohua;Li Yu;Zeng Xierong
本征点缺陷对提高V2VI3多晶材料的热电性能起着核心作用。然而，由于类施主效应，在粉末细化过程中本征点缺陷的控制是具有挑战性的。本文提出了一种系统的方法，通过工程放电等离子烧结和热变形温度来控制类施主效应。以高电子浓度的Bi2Te2.85Se0.15多晶合金为例进行了验证。通过适当调节烧结或变形温度，可使n型Bi2Te2.85Se0.15多晶的Seebeck系数降低，这是由于粉末细化后的强类施主效应所致。通过热变形的回复作用，进一步提高了Seebeck系数，在410 K时获得了最大值zT = 1.0。本研究结果为通过热控制类施主效应开发更高性能的V2VI3多晶材料提供了思路。
Intrinsic point defect plays a core role in improving thermoelectric performance of V2VI3polycrystalline materials. However, the control of intrinsic point defect is challenging during powder refinement due to the donor-like effect. This paper shows a systematic approach to thermal control the donor-like effect via engineering spark plasma sintering and hot deformation temperature. Bi2Te2.85Se0.15polycrystalline alloy with high electron concentration was chosen as example to validate the method. The low Seebeck coefficient ofn-type Bi2Te2.85Se0.15polycrystalline, arising from strong donor-like effect after powder refinement, was enhanced by recovery role induced reduction in electron concentration through proper tuning sintering or deforming temperature. Repetitive hot deformation was applied to further improve the Seebeck coefficient via the recovery role and a maximumzTof 1.0 is obtained at 410 K. The present results give insights into developing higher performance V2VI3polycrystalline materials through thermal control the donor-like effect.