Transient and Steady Photoelectric Responses of LB Films Containing Amphipathic Porphyrin and Redox Chromophores

Sandwich type cells of LB films containing amphipathic porphyrin monolayers (P) and carbazole or alloxazine derivtives in monolayers adjacent to P were constructed between IT0 and A1 electrodes. The acation spectra of steady and transient photocurrents corresponded well with the absorption spectrum of porphyrin in LB films. Transient photocurrents upon excitation of porphyrins with the the absortion films, which showed a fast rise and a slow exponential decay. The decay behavior and the values of steady photocurrents depended on the nature of redox cheomophores and the extent of their aggregation together with the bias voltage. From these results, redox chromphores were concluded to retard the decay of photocarriers in monolayers adjacent to LB films containing porphyrin which generated them.