Fabrication and photovoltaic properties of fullerene and copper phthalocyanine derivative mixed langmuir-schaefer films

Surface pressure-area isotherms of mixed floating film of fullerene (C₆₀) and tri-(2,4-di-t-amylphenoxy)-(8-quinolinolyl) copper phthalocyanine (CuPc) were investigated at different molar compositions at air-water interface. The shapes of these isotherms and estimated areas per molecule are shown dependent on the molar compositions. C₆₀/CuPc mixed multilayers were fabricated onto various solid substrates by using Langmuir-Schaefer (LS) technique, and characterized by UV-VIS spectroscopy, electrochemical and photoelectrochemical measurements respectively. Uniform LS films were formed when the molar composition was less than 1:1 (C₆₀ : CuPc). UV-VIS spectroscopic measurements showed that there was no distinct interaction between phthalocyanine and C₆₀ molecules at ground state either in solutions or in solid films. However, electron transfer appears to have occurred between two kinds of molecules under light illumination. Photoelectrochemical study revealed that phthalocyanine and C₆₀ mixed system could be a potential candidate for photovoltaic applications.