等离激元介导电子发射纳米结构及物理机制研究

高效的电子发射阴极是发展新一代高频段、高功率、微型化真空电子器件的核心前提，开发新型的真空电子发射方法和相关电子发射阴极材料是实现该目标的有效途径。本项目提出一种光电共激励和等离激元介导的电子发射新方法，系统开展基于新方法的电子发射材料制备、特性与物理机制、阴极应用基础问题的研究。基于光响应、局域电场模拟计算和纳米材料自组装制备，设计并合成一系列等离激元纳米颗粒与高长径比场发射体构成的电子发射纳米复合结构。发展面向薄膜与阵列的电子发射特性表征方法和面向微区电子发射结构的原位表征方法，系统研究材料的电子发射特性，包括光调控、电流、效率、功耗、均匀性、超快响应、能量散度、稳定性等特性；分析构效关系，定量揭示物理机制，建立电子发射普适方程。依据构效关系和结合阴极应用，优化电子发射纳米结构，研究高效电子发射阴极材料制备方法，为新一代真空电子器件核心部件技术需求提供新方法和新材料。

An electron emission cathode with high efficiency is the core premise of developing a new generation of high frequency, high power and miniaturized vacuum electronic devices. The development of new vacuum electron emission methods and related cathode materials is an effective way to achieve this goal. In this project, we propose a new method of electron emission under the optical-electric excitation and the plasmonic mediation. We are going to carry out the research on the preparation, characteristics and physical mechanism of electron emission materials and the fundamental problems of cathode application based on this new method. Through the simulation of optical response and localized electric field, as well as the self-assembly of nanomaterials, a series of electron emission nanocomposite structures composed of plasmonic nanoparticles and high-aspect-ratio field emitters will be designed and synthesized. The characterization method of electron emission properties for thin films and arrays and in-situ characterization of electron emission structures for micro-regions will be developed, respectively. The electron emission properties of materials are going to be systematically studied, including light regulation, emission current, efficiency, power consumption, uniformity, ultra-fast response, energy spread and current stability. The structure-activity relationship will be analyzed, the physical mechanism will be revealed quantitatively, and the universal equation of electron emission will be established. According to the structure-activity relationship and the application of cathode, the electron emission nanostructure will be optimized, and the preparation method of the efficient electron emission cathode material will be studied, so as to provide new methods and new materials for the technical requirements of the core components of the new generation of vacuum electronic devices.