Enhanced performance in polymer photovoltaic cells with chloroform treated indium tin oxide anode modification

Enhanced performance of a poly(3-hexylthiophene):(6,6)-phenyl C(61) butyric acid methyl ester bulk heterojunction polymer photovoltaic cell is reported by modifying the indium tin oxide (ITO) anode with chloroform solution. Instead of the traditional UV-ozone treatment, the optimized chloroform modification on ITO anode can result in an enhancement in the power conversion efficiency of an identical device, originating from an increase in the photocurrent with negligible change in the open-circuit voltage. The performance enhancement is attributed to the work function modification of the ITO substrate through the surface incorporation of the chlorine, and thus improved charge collection efficiency. (C) 2011 American Institute of Physics. [doi:10.1063/1.3601853]