Improved thermoelectric performance of Bi2Se3 alloyed Bi2Te3 thin films via low pressure chemical vapour deposition
Improved thermoelectric performance of Bi2Se3 alloyed Bi2Te3 thin films via low pressure chemical vapour deposition
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DOI：
10.1016/j.jallcom.2020.156523
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发表时间：
2020-08
影响因子：
6.2
通讯作者：
Daniel W. Newbrooka;Stephen P. Richardsb;Victoria K. Greenacreb;A. Hectorb;W. Levasonb;Gillian Reidb-Gillian-Reid
中科院分区：
文献类型：
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作者：
Daniel W. Newbrooka;Stephen P. Richardsb;Victoria K. Greenacreb;A. Hectorb;W. Levasonb;Gillian Reidb-Gillian-Reid
热电发电机对于自主传感器系统是有吸引力的，其中定期更换电池不仅会导致维护成本的增加和操作的不连续性，而且还会破坏真正自主系统的概念。微型热电发电机利用薄膜材料进行能量收集，这可以大大减少材料的使用量，这对碲等稀有元素尤其重要。采用单源前驱体CVD法成功地制备了Bi_2Te_3薄膜。通过合金化Bi_2Se_3前驱体，存款沉积三元Bi_2 Te_3-xSex，提高了薄膜的热电性能。调整三元系统的组成以优化载流子浓度和迁移率的组合，相对于Bi 2 Te 3，在300 K下使热电功率因子增强三倍，在500 K下增强六倍。用Se取代Te的这种改善被认为是由于施主效应以及由这种取代引起的点缺陷。
Thermoelectric generators are attractive for autonomous sensor systems where regular battery replacement would not only cause an increase in the maintenance costs and discontinuity in the operation, but also destroy the concept of a truly autonomous system. Micro-thermoelectric generators utilise thin films of material for energy harvesting which can greatly reduce the amount of material used, which is especially important for rare elements such as tellurium. Thin films of Bi2Te3were successfully preparedviaa single source precursor CVD method. The thermoelectric performance of these films is improved by alloying a Bi2Se3precursor to deposit ternary Bi2Te3-xSex. The composition of the ternary system is tuned to optimise the combination of carrier concentration and mobility to give a three-fold enhancement of the thermoelectric power factor at 300 K, and six-fold enhancement at 500 K, with respect to Bi2Te3. This improvement from the substitution of Te with Se is believed to be due to donor effects, as well as point defects caused by this substitution.