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TitleThe effects of oxygen concentration and light intensity on the photostability of zwitterionic chromophores
Publication TypeJournal Article
Year of Publication2009
AuthorsRaymond, S.G., Williams G.V.M., Lochocki B., Bhuiyan M.D.H., Kay A.J., and Quilty J.W.
JournalJournal of Applied Physics
Date Published2009
ISSN00218979 (ISSN)
KeywordsAmorphous films, Amorphous polycarbonates, Average numbers, Chromophores, Figure of merit, Ground state bleaching, Host-guest, Light, Light intensity, Low oxygen partial pressure, Optical intensities, Organic chromophores, Oxygen, Oxygen concentrations, Oxygen content, Oxygen partial pressure, Partial pressure, Photo-stability, photodegradation, Photoluminescence intensities, Quantum efficiency, Second-order nonlinear optical, Semiconductor quantum dots
AbstractPhotostability measurements at different oxygen partial pressures and light intensities have been made on host-guest films containing amorphous polycarbonate and an organic chromophore with a high second order nonlinear optical figure of merit. We find that the photodegradation quantum efficiency dramatically increases with increasing oxygen partial pressure. At very low oxygen partial pressures (8× 10-6 bar) the average number of photons required to photodegrade a chromophore is as high as 2× 108 at 655 nm. The photodegradation quantum efficiency in air is observed to decrease with increasing optical intensity. We show that this is due to a reduced oxygen content in the film caused by chromophore photodegradation rather than ground state bleaching. There is an anomalous increase and then decrease in the photoluminescence intensity that cannot easily be explained. © 2009 American Institute of Physics.

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