EFFECT OF TEMPERATURE ON PHOTOCONDUCTION AND LOW-FREQUENCY CAPACITANCE MEASUREMENTS ON BETA-CUPC PHOTOVOLTAIC CELLS

The electrical properties of In/beta-CuPc-PVAc/Au (where CuPc is coppe r phthalocyanine and PVAc is polyvinylacetate) devices in the dark and under illumination have been studied. The temperature dependence of t he photocurrent was attributed to a high trap density. Electron traps located at 0.25 eV below the conduction band have been observed. Schot tky barrier parameters of the cell in the dark and under different mon ochromatic light intensities have been determined by a low frequency d ifferential capacitance method. Light intensity increased significantl y the space change density, which is a major concern as a possible lim iting factor for the performance of organic solar cells.