Research Interest:
My research involves photostability measurements in organic thin films. Plasmonic focusing of EM fields near noble metal nanoparticle surfaces allows for a tunable means by which acceleration of absorption and emission rates is possible for appropriately positioned fluorescent molecules. A quantitative analysis of radiative rate correlation to photostability enhancements has yielded a breakdown which shows that organic thin films, and especially plasmon enhanced organic thin films, offer additional stability over what would be expected purely by examination of radiative rates. This additional photostability is due at least in part to an uncoupling of the absorption and emission sites comprising the film with the resulting energy transfer network funneling excitons to lowest energy state sites for emission. As such a cascade would selectively burn out lowest energy sites first, photostability over that expected from a linear degradation of the ensemble with respect to lifetime is possible if most absorbed photons are relaxed at sites in the cascade prior to reaching the lowest energy emitter site and the replacement of photodegraded lowest site emitters is through fluorophores which are increasingly less energetically stable and exhibit faster relaxation rates.