Electric-Field-Induced Fluorescence Quenching in a Metal-Insulator-Metal Device Composed of Flavin-Porphyrin Hetero-Type Langmuir-Blodgett Films

Abstract

Photoinduced electron transfer processes in flavin-porphyrin hetero-type Langmuir-Blodgett films were investigated in terms of the electric-field-induced quenching of flavin fluorescence. The dependence of the fluorescence quenching on the applied voltage corresponded well with the rectifying photocurrent-voltage characteristics. The rate of fluorescence quenching, which is approximately 1 min À1 , was found to be slow. It was concluded that the fluorescence quenching was attributed to reduced flavin molecules in the flavin monolayers generated by the electron transport process after the charge separation.