The addition of FeO nanoparticles to BiSe nanocomposites resulted in a significant increase of the thermoelectric figure of merit at room temperature from 0.14 in BiSe to 0.21 in BiSe with added 5 % volume of FeO nanoparticles. The main contributor to the improved is the large increase in carrier concentration, hence increased electrical conductivity. Electron microscopy investigation revealed chemical changes in the BiSe leading to segregation of Bi to the interface with the FeO nanoparticles. The fact that the altered Bi/Se proportion was constrained close to the grain boundaries resulted in a mild reduction of the Seebeck coefficient, less than what is expected from simple band structure models for the same increase in carrier density. The addition of FeO in relatively small volume fraction allowed to both decrease the thermal conductivity and increase the power factor in a BiSe material, the latter more intensely than usual substitution methods.

中文翻译：

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Bi2Se3-Fe3O4 纳米复合材料的晶界化学和增强的热电性能


在 BiSe 纳米复合材料中添加 Fe3O 纳米颗粒后，室温下的热电品质因数显着增加，从 BiSe 中的 0.14 增加到 BiSe 中添加 5% 体积的 Fe3O 纳米颗粒的 0.21。改进的主要贡献者是载流子浓度的大幅增加，从而增加了电导率。电子显微镜研究显示 BiSe 中的化学变化导致 Bi 偏析到 Fe3O 纳米颗粒的界面上。事实上，改变的 Bi/Se 比例被限制在晶界附近，导致塞贝克系数略有降低，低于简单能带结构模型对于载流子密度相同增加的预期。添加相对较小体积分数的 FeO 可以降低 BiSe 材料的热导率并提高功率因数，后者比通常的替代方法更强烈。