Transient Photocurrent Based on Photoinduced Electron Transfer Processes in Flavin-Porphyrin Hetero Langmuir-Blodgett Monolayers

Abstract

Dynamic processes of photoinduced electron transfer in flavin-porphyrin hetero Langmuir-Blodgett monolayers, which are characterized both by the electronic properties of functional groups and by the structure of molecular organization, have been studied in terms of transient photocurrent properties. From an analysis of transient photocurrent with a kinetic model based on the organic quantum well structure, we can conclude that the photocarrier generation process is mainly due to charge separation from photoexcited flavin to porphyrin at the flavin-porphyrin molecular heterojunction, and that the charge shift in monolayers and charge transfer between monolayers and an electrode are controlled by applied electric field.