物理学科Seminar 161讲
报告题目：Functionalized Carbon Nanotubes for Thermionic Emission and Thermionic Cooling（功能碳纳米管的热离子发射及热离子冷却）
报告人：Prof. Feng JIN （金峰教授）， Ball State University, US
地点：校本部G309
时间：2013年6月18日 上午10：00
摘要：Carbon nanotubes (CNTs) are natural field emitters; their unique geometry and high aspect ratio give rise to a high field enhancement factor . The field emission properties of CNTs have been extensively studied in recent years. However, less explored is the potential of utilizing CNTs in thermionic emission. In this talk, I will present a new type of thermionic emitter based on functionalized CNTs and its superior electron emission properties. The basic structure of this emitter is such that it consists of CNTs with a low work function emissive thin film surface coating. The low surface work function combined with a large Schottky effect introduced by CNTs results in a strong new type of thermionic emission - field enhanced thermionic emission, which is orders of magnitude greater than that from a typical thin film thermionic emitter. Also, such strong thermionic emission of hot electrons carries away significant amount of energy from the surface, and thus leads to a large cooling effect on the emission surface. Temperature drop as large as 100 degree has been observed and such a thermionic cooling effect also opens doors for new types of cooling devices in microelectronics and beyond. Detailed fabrication techniques and process for the emitter will be presented, along with the ideas and results of this field enhanced thermionic emitter. Its applications in electron sources and thermionic cooling and energy conversion will also be discussed.