PHOTOELECTROCHEMICAL STUDY ON COPPER PHTHALOCYANINE FILMS

Copper phthalocyanine (CuPc) films vacuum-deposited on SnO//2 electrodes develop photocurrents by illumination with monochromatic light. Their action spectra reflect the absorption spectrum of the CuPc film. The effect of the thickness of the CuPc film and the illumination direction dependence of photocurrent action spectra are observed. Anodic photocurrents arise from excitons generated near the SnO//2/CuPc interface and are consistent with the ordinary dye sensitization scheme. Cathodic photocurrents are attributable to excitons which are generated and dissociate in the bulk of CuPc. Hydroquinone, p-quinone, and O//2 act as a reducing or an oxidizing agent. p-Quinone interacts with CuPc preferentially. Transient behaviors and open circuit photovoltages are also discussed.