Investigation On The Photophysical Properties Of Organic Conjugated Fluorescent Dye Coumarin 6(C-6)

Organic conjugated fluorescent dyes have very high fluorescence yield, which is an important indicator of the characteristics of fluorescent dyes, and are also respective in their photophysical processes. Thus, organic conjugated fluorescent dyes can be a kind of important species of fluorescent. In order to do further study of the photophysical processes of the organic conjugated fluorescent dyes, we choose a kind of conjugated dye Coumarin 6(C-6) as a case to study, try to figure out the photophysical characteristics of C-6 dye molecules by systematical study of the aspects of its steady state luminescence, fluorescence yield and fluorescence lifetime. The following main issues would be discussed in the paper.1、We prepare the nanoparticle(NP) based on conjugated molecules(Coumarin 6, C-6), which is considered to be mesoscopic aggregate, in order to build a bridge linking monodisperse state(solution state) and macroscopic aggregate(powders state). Their spectral features involving steady spectral data, dynamic feature and fluorescence quantum yield have been compared in detail. All dynamic data are modelled by continuous rate distribution function. The final result shows an elementary evolution process of conjugated molecules at different intermolecular interaction.2、We compare the fluorescence characteristics of conjugated molecules(coumarin 6, C-6) in different conditions: in solution, in state of aggregation and in state of opal photonic crystal(PC) of polymethyl methacrylate(PMMA). Also, we do research on the manipulation mechanism of PCs on C-6. It can be found that the PCs effectively suppress the aggregate-induced fluorescent quenching of C-6 by breaking the inter-molecular interaction. And the fluorescence characteristics of C-6 can also be regulated by changing the location of photonic stop band(PSB) in photonic crystal. We use the continuo us rate distribution model to analyze the emission traces of C-6. The results indicates that the control of fluorescence characteristics of C-6 in PCs depends on the mesh microporous structure and the PSB of PCs.