Picosecond photoionization and geminate recombination in an organic donor—acceptor complex

✍ Scribed by C.A. Walsh; D.M. Burland

• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 690 KB
• Volume: 195
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(92)85608-d

✦ Synopsis

The initial steps involved in the charge separation process in thin films of the organic charge-transfer complex formed from poly-N-vinylcarbazole (PVK) and 2,4,7-trinitro-9-fluorenone (TNF) are observed directly using polarization selective picosecond transient grating techniques. When forming a grating with parallel polarized writing beams, a nonexponential decay of the transient grating signal is observed. When forming a grating with perpendicularly polarized writing beams, the decay of the transient grating signal is observed to increase and to be described adequately as a single exponential. These transient grating signals have been investigated as a function both of an applied electric field and as a function of the TNF: PVK ratio. All of these results are consistent with a four-level kinetic model that includes charge hopping, geminate recombination, and field-assisted charge separation.