Fluorescent dopant

A series of red fluorescent dyes has been recently reviewed by Chen [204], The red fluorescent dopants, according to their structural characteristics, are summarized as ... 

Another important early advance made by Tang et al. [7] is the use of fluorescent doping, i.e., the addition of a small percentage of an emissive fluorescent material into a host matrix. This can be used to alter the color of emission, in addition to improving the efficiency and the lifetime of devices. The technique of simultaneously vapor depositing the host and the fluorescent dopant material is now widely used in the field of OLEDs. 

Depth-distribution of fluorescent dopants in cast polymer film (4) Fluorescence spectra of poly(N-vinylcarbazole) (PVCz) film doped with perylene are shown in Fig. 6. They consist of two broad structureless excimer bands of the polymer with a shoulder at 375 nm and a peak at 420 nra, and perylene band with a vibrational structure above 450 nm. It is worth noting that the perylene fluorescence intensity under the TIR condition is relatively weaker than that under the normal one. Since the boundary surface is selectively excited under the former condition, the structure near the surface should be different from the bulk. It is well known that the excitation energy migrates over carbazolyl chromophores and is trapped in the doped perylene efficiently. Therefore, the present result means that energy migration efficiency in the host polymer and/or the dopant concentration are a function of the depth from the interface. 

Systematic studies on the nature/dynamics of the excitation processes in the UV ablation of polymers have been reported by Masuhara and co-work-ers [61-63]. To this end, they have relied on the use of dopants dispersed within polymers. Given the relevance of their approach to the topic of the present article, their work will be presented in some detail. Time-resolved absorption and luminescence spectroscopies have been used to probe the dynamics of electronic excitation and deexcitation of the dopants. In the irradiation of fluorescing dopants (biphenyl or phenanthrene), the total emis-... 

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