典型“金属纳米粒子-分子”体系表面增强荧光光谱及动力学性质的理论研究

由于表面等离激元的增强电场效应，金属纳米粒子与邻近分子间可发生强烈的电磁耦合，由此导致的表面增强吸收、辐射等光学现象在生化传感器、光电子器件、太阳能利用等领域具有非常广泛的应用，因此对金属纳米粒子-分子体系的光响应性质进行全面深入的理论模拟研究具有重要的科学和实际意义。本项目拟以几个典型的表面等离激元增强荧光体系为例，在同时考虑分子-金属间及分子间电磁耦合相互作用的前提下建立多尺度、多物理的理论模型，通过对Maxwell-Lorentz-Liouville耦合方程进行有限元数值求解，模拟体系的吸收和发射光谱，考察分子的电子跃迁动力学过程和金属-分子间的能量转移过程，阐明体系动力学性质与光谱学性质之间的内在联系；揭示金属、分子性质及金属-分子间电磁耦合作用对体系光响应性质的影响，为高灵敏分子探测技术的发展、新颖光电子器件的设计、太阳能利用效率的提升等奠定理论基础。

Electromagnetic coupling between metallic nanoparticle and adjacent molecules, due to the electric field-enhancing effect of surface plasmon, leads to optical phenomena such as surface-enhanced absorption and radiation with wide applications in biochemical sensing, phoelectron device and solar energy harvesting. A comprehensive and in-depth theoretical study on the photo-response properties of metallic nanoparticle-molecule systems is of crucial scientific and practical significance. In this project, taking several typical surface-enhanced fluorescence systems as example, we will construct multi-scale and multi-physics theoretical model with metal-molecule and inter-molecule coupling taken into account, solve the resulting coupled Maxwell-Lorentz-Liouville equations using the finite element method, and obtain the absorption and emission spectrum; study the electron excitation dynamics and energy transfer between metal and molecules, clarifying the underlying correlation between dynamical and spectral properties of system; uncover the influence of metal, molecule properties and the electromagnetic coupling on photo-response properties of system, laying foundations for development of highly sensible molecule detection technique, design of novel optoelectronic devices, improvement of solar energy harvesting efficiency etc.