Water-soluble poly(3,4-ethylenedioxythiophene)/nano-crystalline TiO2 heterojunction solar cells

Nanocrystalline titanium dioxide (TiO2) thin films were prepared by the sol–gel method and were then used to fabricate an indium-tin oxide (ITO)/nano-crystalline TiO2/poly(3,4-ethylenedioxythiophene) (PEDOT)/Au device. The junction thus obtained shows a rectifying behavior. Their current–voltage (I–V) characteristics in dark indicate that a heterojunction at the nano-crystalline TiO2/PEDOT interface has been created. The measured open-circuit voltage (Voc) and short-circuit current (Isc) for the device under illumination with 50 mW/cm2 light intensity under AM 1.5 conditions (device dimension was 1 cm2) are Voc=0.39 V, Isc=54.9 μA/cm2, the filling factor (FF)=0.429 and the energy conversion efficiency (η)=0.03%.