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TitleThe effects of excited state lifetime, optical intensity, and excited state quenchers on the photostability of zwitterionic chromophores
Publication TypeJournal Article
Year of Publication2011
AuthorsWilliams, G.V.M., Kutuvantavida Y., Janssens S., Raymond S.G., Do M.T.T., Bhuiyan M.D.H., Quilty J.W., Denton N., and Kay A.J.
JournalJournal of Applied Physics
Date Published2011
ISSN00218979 (ISSN)
KeywordsAmorphous films, Amorphous polycarbonates, Beta carotene, Chromophores, energy transfer, Enhancement factor, Excited state lifetimes, Excited states, Excited-state energy, Fiber optic sensors, Nonlinear optic chromophores, Nonradiative decays, Optical correlation, Optical intensities, Oxygen, Oxygen content, Photo-stability, Photobleaching, PL lifetime, Singlet excited state
AbstractPhotoluminescence (PL) and photostability measurements have been made on thin films containing the 2nd order nonlinear optic chromophore, PYR-3, and amorphous polycarbonate (APC). We find that the PYR-3 singlet excited state PL lifetime systematically decreases with increasing PYR-3 concentration, which may be due to PYR-3 excited state energy transfer to non-radiative decay sites. There is no correlation between the PL lifetime and the photostability for low optical intensities, and we find that the photobleaching data cannot be modeled with a single photodegradation quantum efficiency. There is an increase in the photostability with increasing optical intensity, and this enhancement is larger for high PYR-3 concentrations. It can be explained by a reduction in the oxygen content by oxygen-mediated photodegradation for the 5 PYR-3/APC films. This also partly explains the enhancement in the 15 PYR-3/APC films, but there is an additional mechanism as well. The photostability can also be improved by adding beta-carotene, which leads to an enhancement factor of greater than 6. © 2011 American Institute of Physics.

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