表面等离激元增强碳纳米管光电器件性能研究

The fabulous electronic and optoelectronic properties of carbon nanotubes (CNTs) make this material advantageous for potential application in infrared (IR) nano light sources and detectors. This project is aimed at further investigating carbon nanotube photoelectronic devices based on the progress in the project “Youth science foundation” from NSFC. Our study is focused on the properties of IR light-emitting diodes and photodetectors of the diode with asymmetric contacts via introducing plasmonic nanostructures. To improve the performance of these devices and make it reach its limit, we need to analyze the factors that determine the device performance and figure out the relevant physical mechanism to optimize the structure design and fabrication process of these devices. The main investigation includes two parts. The first is focused on improving the electroluminescence efficiency of CNT light-emitting devices. We plan to study the physical mechanism on quantum efficiency of light emission, exciton diffusion and decay, and surface plasmon coupling between metal nanostructures and excitons, and surface plasmon resonance affection on the radiative recombination efficiency in CNT. For the CNT infrared detectors, the plasmonic metal nanostructures are used to enhance the light absorption of CNT and improve the performance of detectors. We investigate the key parameters such as quantum efficiency, responsivity of the detector which are determined by the light absorption and exciton decay of CNT. It needs us to figure out the related physical mechanism and further improve the performance of photodetectors. The objective of this project is to develop high performance carbon nanotubes based infrared light sources and detectors, which is of great significance for photoelectric integration in the future.

碳纳米管具有优异的电学和光学特性，是构建新型红外纳米光源和光探测器的重要候选材料。本项目拟在青年科学基金项目取得的工作进展基础上进行深入研究，主要采用表面等离激元纳米结构增强非对称接触电极构建的碳管发光二极管和光探测器的性能，分析影响器件性能的因素，优化完善器件的结构和工艺，使其性能达到国际先进水平。内容包括：（1）在发光器件方面，研究发光效率相关物理机制、激子的扩散和复合特性、金属纳米结构中的表面等离激元与激子之间的耦合以及对激子辐射复合效率的影响等，揭示其物理规律，为提高器件发光效率提供思路。（2）在红外光探测器方面，采用表面等离激元金属纳米结构增强碳管的光吸收，系统研究器件的量子效率、响应度、探测度等关键参数相关的光吸收和激子分离过程，阐明其物理机制，为进一步提升光探测器性能奠定基础。本项目的目标是发展出基于碳管的高性能红外光源和光探测器，对将来的光电一体化集成具有重要意义。

半导体碳纳米管是直接带隙材料，其在光电一体化集成，低成本、高性能短波红外探测等方面具有巨大的应用前景。本项目主要研究基于碳纳米管薄膜器件的发光和光电探测特性，通过等离激元纳米结构对器件的性能进行高效调控，获得了以下研究成果。.（1）在碳管发光器件研究方面：重点研究手性富集的碳纳米管薄膜的发光特性和相关物理机制。系统研究器件发光光谱特性以及发光效率的影响因素，优化器件的结构和工艺，获得低工作电压、高效率的红外发光光源。.（2）研究了高纯碳纳米管薄膜红外探测器以及多级级联红外探测器的相关性能，包括不同波长的响应度、量子效率以及探测度等。研究了自组装定向排列高纯半导体碳管薄膜构建的红外探测器性能，包括不同波长的响应度、量子效率以及探测度等。研究结果发现了红外光探测器中等离激元纳米结构对器件性能的影响规律，可以通过等离激元结构优化提高碳纳米管红外探测器的性能。