Top illuminated inverted organic ultraviolet photosensors with single layer graphene electrodes

Inverted, top-illuminated organic photodiodes are demonstrated using transparent electrodes including single layer graphene (SLG) and thin gold or silver with poly(3-hexylthiophene) and 1 -(3-methoxycarboyl)-propyl-1-phenyl-(6,6)C-61 as active layer. The devices are free of both indium-tin-oxide and poly(3,4-ethylenedioxythiophene): poly(styrene-sulfonate). The maximum solar power conversion efficiencies were 0.3% for SLG due to its series resistance and similar to 2% for gold and silver. The organic photodiodes with SLG electrodes had good external quantum efficiency at incident illumination less than 10 mW/cm(2) and better performance than gold and silver at wavelengths below 300 nm making them attractive for ultraviolet photosensors. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4733299]