Photoelectric conversion property of monolayer films of fullerene tetracarboxylic acid derivatives

An amphiphilic C-60 tetracarboxylic acid (1) and its tetramethyl eater (2) have been prepared. They form stable Langmuir monolayer at the air-water in terface, which can be deposited on semiconducting transparent ITO electrode s. The photoelectric responses of the monolayer-modified electrodes are mea sured in a conventional photoelectrochemical cell. The anodic photocurrent observed corresponds to an electron transfer from the electrolyte through L B film to the electrode. The action spectrum of the photocurrent is in good agreement with the absorption spectrum of the modified ITO electrode, conf irming that the excited C-60 derivatives act as the photoactive species in the photoinduced electron transfer process. Factors influencing the photocu rrent have been studied such as the intensity of the irradiation, concentra tion of redox agent in the electrolyte solution, bias voltage and pH. (C) 1 999 Elsevier Science S.A. All rights reserved.