Photoinduced intermolecular charge transfer (PICT) in donor/acceptor systems has been investigated as an approach to the design of new optical limiting (OL) materials. Solution of cyanines or porphyrins (as sensitizers) and viologen derivatives (as electron acceptors) were used in these studies. Picosecond time-resolved fluorescence measurements were carried out to estimate the charge-transfer rate in these donor/acceptor systems. The radical-ion absorption bands were identified using spectroelectrochemistry. Nonlinear transmission measurements with picosecond and nanosecond laser pulses were utilized to determine the effective photo-induced to ground-state absorption cross-section ratio of the sensitizers alone and the sensitizer/acceptor systems. Our studies are consistent with optical limiting by PICT in solution and indicate a substantial radical-ion yield in the systems examined.
|Original language||English (US)|
|Number of pages||8|
|Journal||Materials Research Society Symposium - Proceedings|
|State||Published - Dec 1 1997|
|Event||Proceedings of the 1997 MRS Spring Meeting - San Francisco, CA, USA|
Duration: Mar 31 1997 → Apr 2 1997