Optimized structure of tubular thermoelectric generators using n-type Bi2Te3 and p-type Sb2Te3 thin films on flexible substrate for energy harvesting
Optimized structure of tubular thermoelectric generators using n-type Bi2Te3 and p-type Sb2Te3 thin films on flexible substrate for energy harvesting
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DOI：
10.1016/j.sna.2020.112199
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发表时间：
2020-10-01
影响因子：
4.6
通讯作者：
Takashiri, Masayuki
中科院分区：
文献类型：
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作者：
Kobayashi, Akihiro;Konagaya, Ryota;Takashiri, Masayuki
热电能量收集作为物联网传感器中的供电手段已经引起了相当大的兴趣。在这项研究中，管状薄膜热电发电机（TTTEGs）开发使用柔性热电薄膜的能量收集。采用射频磁控溅射法在聚酰亚胺片上沉积了n型Bi 2 Te 3和p型Sb 2 Te 3薄膜，并进行了热退火处理。在形成金属电极以连接p-n对之后，将柔性薄膜发生器卷起并放置在塑料管中。假设在优化设计中，TTTEG将部分浸入热水中，使用计算流体力学计算TTTEG中的温度分布。计算表明，在水面附近出现了陡峭的温度梯度，这也在实验测量中观察到。因此，我们制备了具有从16至36 mm范围内的不同膜长度的TTTEG，同时膜宽度和管半径分别保持在2 mm和7.5 mm。具有16 mm膜长度的TTTEG表现出最高的热电性能，即，在20 K的温差下，开路电压为122.9 mV，最大输出功率为306.8 nW。出现这种趋势是因为短薄膜TTTEG有效地利用了陡峭的温度梯度，并且具有小的电路电阻。(C)2020爱思唯尔B. V.保留所有权利。
Thermoelectric energy harvesting has garnered considerable interest as a means of power supply in Internet of Things sensors. In this study, tubular thin-film thermoelectric generators (TTTEGs) were developed using flexible thermoelectric films for energy harvesting. The strip-shaped n-type Bi2Te3 and p-type Sb2Te3 thin films were deposited on a polyimide sheet using radio-frequency magnetron sputtering, followed by thermal annealing. After the formation of metal electrodes to connect p-n pairs, the flexible thin-film generator was rolled and placed in a plastic tube. Assuming that the TTTEGs would be partially immersed in hot water in the optimal design, the temperature distributions in the TTTEGs were calculated using computational fluid dynamics. The calculations indicated that a steep temperature gradient occurred near the water surface, which was also observed in an experimental measurement. Therefore, we prepared TTTEGs with different film lengths ranging from 16 to 36 mm while the film width and radius of tube were maintained at 2 mm and 7.5 mm, respectively. The TTTEGs with a film length of 16 mm exhibited the highest thermoelectric performance, i.e., an open-circuit voltage of 122.9 mV and a maximum output power of 306.8 nW, at a temperature difference of 20 K. This trend occurred because the short-film TTTEG effectively utilized the steep temperature gradient and had a small circuit resistance. (C) 2020 Elsevier B.V. All rights reserved.