Electronic energy transport in nanomaterials: influence of host structure

摘要

The transport of electronic energy within molecular nanomaterials generally entails a multi-step migration of excitation between chromophores possessing readily distinguished and characterized absorption and fluorescence spectra, such that each step of the migration is well described by a standard F?rster model. When the associated chromophores are sited within a superstructure of significantly different composition, the simplest picture of the host influence is commonly given in terms of a dependence on local refractive index. Such a representation is deployed for structures ranging from photosynthetic systems to a wide variety of multi-chromophore materials including light-harvesting dendrimers, but the oversimplification fails to register the electronic effect of material specifically in the vicinity of the energy transfer. In photosynthetic systems, for example, successive stages of energy transport can occur in very different portions of a protein superstructure. In this initial analysis the methods of quantum electrodynamical analysis are brought to bear on these general issues. Exploiting a state-sequence methodology, the development of theory extends earlier studies by several research groups. It leads to new results that allow the identification of specific optical and electronic attributes that can locally expedite or inhibit energy transport. One newly discovered feature is a significant interplay of influence between the local architecture, as determined by the disposition and relative orientations of the donor and acceptor chromophores, with the structural symmetry of the host material within which they reside.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.