Fabrication and their photoelectric conversion properties of two kinds of self-assembled monolayers and Langmuir-Blodgett film of mono-substituted C₆₀-malonic acid

Two kinds of self-assembled monolayer (SAM) and a Langmuir-Blodgett film of fullerene derivative C₆₁(COOH)₂ that have the photoelectric conversion property were first reported here. The SAMs were either fabricated directly on hydrophilic indium-tin-oxide (ITO), quartz, and mica by esterification reaction or on the aminopropylsilanated substrates by amide bonds. The SAMs were characterized by contact angle, AFM, UV spectrum and cyclic voltammetry. The film thickness calculated by molecular mechanic with the MM2 method in Molgen 4.0 coincided with that obtained by AFM measurement, indicating the formation of monolayer. All of three systems can generate stable cathodic photocurrent. The separated charge loss process in our systems is monomolecule recombination.