STEADY-STATE PHOTOVOLTAIC AND ELECTROREFLECTIVE SPECTRA IN AL VANADYLPHTHALOCYANINE (VOPC, IN PHASE-II) INDIUM-TIN-OXIDE (ITO) SANDWICH CELL

The polycrystalline VOPc films in phase ii have been fabricated on an indium-tin-oxide-glass substrate. X-ray diffraction pattern and visibl e absorption spectrum have been used to characterize the packing struc ture of VOPc molecules. The photovoltaic action spectrum of Al/vanadyl phthalocyanine (in phase II)/indium-tin-oxide (Al/VOPc/ITO) sandwich cell under different modulation frequencies of illuminating light have been measured. The VOPc film acts as a p-type semiconductor. The phot ovoltage is mainly generated at the Al/VOPc interface. The charge tran sfer excitons and Frenkel excitons have been revealed by electric modu lation reflective spectroscopic technique, both of them may play an im portant role in the photovoltaic process. (C) 1998 Elsevier Science S. A. All rights reserved.