功能化碳纳米管薄膜的热离子冷却效率

严学俭

Thermionic cooling efficiency of functionalized carbon nanotube thin films

功能化碳纳米管薄膜的热离子冷却效率

Journal of Vacuum Science & Technology B 36, 051804 (2018);

https://doi.org/10.1116/1.5041762

Feng Jina) and Dustin Carter
Hide Affiliations
Department of Physics and Astronomy, Ball State University, Muncie, Indiana 47306
a)Electronic mail: fjin@bsu.edu

ABSTRACT
摘要

A large thermionic cooling effect is observed from a functionalized carbon nanotube cathode surface, and the cooling efficiency, defined as thermionic cooling power as a percentage of total input heating power to the surface, is reported. The cathode consists of a thin tungsten ribbon covered with low work function barium strontium oxide coated carbon nanotubes. It has both a low work function surface and a large Schottky field effect induced by the carbon nanotubes. The combination of the two leads to a strong thermionic emission and hence a relatively large thermionic cooling effect and high cooling efficiency. Detailed measurements of the cathode temperature profiles are presented together with the analysis of the cooling efficiency. The highest cooling efficiency obtained in this study is 5.9% at 1099 °C of cathode temperature and 114.5 mA of thermionic emission current. The dependencies of the cooling efficiency on the cathode temperature and on the emission current are also presented. Prospects of further improvements are discussed as well.

        本研究工作从功能化的碳纳米管阴极表面观察到显著的热离子冷却效应，并且报道了其冷却效率，后者被定义为作为加到表面的总输入加热功率的百分比占比的热离子冷却功率。阴极由薄钨丝带组成，丝带上覆盖了涂覆有低功函数的氧化钡锶的碳纳米管。它具有低功函数表面和由碳纳米管引起的大的肖特基场效应。这两者的组合导致了强烈的热电子发射，因此具有相对显著的热离子冷却效果和高冷却效率。本文提供了阴极温度曲线的详细测量结果以及对冷却效率的分析。在该研究中获得的最高冷却效率在阴极温度1099 °C和114.5mA热电子发射电流条件下为5.9%。本文还给出了冷却效率对阴极温度和发射电流的依赖性，并且讨论了进一步改进的前景。