Organic solar cells of hydroxy squarylium

The photovoltaic properties of Schottky barrier solar cells made from thin films (100–1000 Å) of the organic dye hydroxy squarylium have been studied. Amorphous and polycrystalline films, prepared by evaporation and solution casting, have strong absorption over the entire visible spectrum. The highest power conversion efficiency measured under AMO white light was 0.1% (0.14 mW/cm2 input intensity); this decreased to 0.02% at 135 mW/cm2. The decrease in η with intensity is characteristic of organic materials, but is usually much more pronounced. For 8500-Å monochromatic light the quantum efficiency was as high as 2.3% and the conversion efficiency was 0.2% (1 mW/cm2).