基于MIM隧穿结实现表面等离激元高频探测的机理与调控研究

In this proposal, to solve the problem of lacking effective way for surface plasmon polaritons (SPPs) high-frequency detection in the field of nano optoelectronic integration, the metal-insulator-metal (MIM) tunneling junctions is adopted. As the time of electron tunneling through a nano-barrier layer is in the femtosecond (fs) order, it is very feasible to achieve the high-frequency detection of SPPs. The relationship of tunneling current with the frequencies and the intensities of SPPs, the MIM junction structure and the driven voltages will be studied. It will reveal the physical processes of local-strength electromagnetic field affecting the change of the barrier and the processes of electron direct-tunneling, field emission tunneling, elastic tunneling and inelastic tunneling. After elucidated the physical mechanism of the MIM tunneling junction detecting the SPPs in high frequency, the feasible ways of controlling the responded-frequency of the MIM junction and improving the photoelectric conversion efficiency will also be explored. This proposal is also helpful for explaining the interaction mechanism of the photons, the SPPs and the electronics in the nano-scale, and useful for promoting the development of the SPPs application in field of nano optoelectronic integration.

为解决目前表面等离激元(SPPs)在纳米光电集成领域内缺乏有效高频探途径的问题，本项目拟利用电子隧穿过程所需时间在飞秒(fs)量级的特性，研究金属-绝缘体-金属(MIM)隧穿结高频探测SPPs的相关物理过程。通过分析隧穿电流随SPPs的频率、强度，隧穿结的几何结构，隧穿电压等因素的变化关系，揭示高频局域强场调制隧穿结势垒函数，影响电子直接隧穿、场发射隧穿、弹性隧穿和非弹性隧穿等基本过程的本质原因。在此基础上，阐释MIM隧穿结探测SPPs的物理机理，并探索调控MIM隧穿结响应频率和提高光电转化效率的可行途径。同时，本项目也有助于从纳米尺度进一步揭示光子、SPPs和电子之间相互作用的物理过程，推动SPPs器件在纳米光电集成领域内的应用发展。

本项目按照项目计划书的研究内容，依次开展了金属纳米网格和纳米尖端SPP振荡模式的数值仿真、MIM电子隧穿器件的整体设计加工和测试、SPP高频探测的电学和光学性能的测试和调控，及器件工作的物理机制探索等相关研究工作。上述研究完成了基于MIM电子隧穿结构探测SPP的基础实验工作，证实了纳米电子隧穿器件在高频微纳光电集成领域内作为光电信号探测和转换方面应用的可行性。通过调整MIM器件中的金属电极栅网尺寸、材料体系、驱动电压及入射光束的偏振特性，可有效控制MIM电子隧穿结构的SPP响应频率和提升能量转化效率。项目初步建立的SPP增强电子隧穿原理可用来解释众多微纳光电器件中的电子跃迁和输运行为，加深对器件工作机制的深层次理论和实验认识。项目的研究结果可为SPP纳米光电子器件集成、高频逻辑器件设计、及光学天线和纳米尖端的超快电子发射等领域提供技术参考。