Indium tin oxide-free and metal-free semitransparent organic solar cells

We report on indium tin oxide (ITO)-free and metal-free semitransparent organic solar cells with a high-conductivity poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) (PH1000) as both the bottom and the top electrodes. The PH1000 film showed a conductivity of 680 +/- 50 S/cm. A ZnO layer was used as an interlayer to produce an electron-selective electrode. The semitransparent devices with a structure of glass/PH1000/ZnO/poly(3-hexylthiophene):phenyl-C(61)-butyric acid methyl ester/PEDOT:PSS (CPP 105 D)/PH1000 exhibited an average power conversion efficiency of 1.8% estimated for 100 mW/cm(2) air mass 1.5 global illumination. This geometry alleviates the need of vacuum deposition of a top electrode. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3499299]