The capability of being processed by low cost, low temperature and efficient roll-to-roll printing processes on flexible
substrates has enabled the organic photovoltaic (OPV) solar cell to become a very promising technology for costeffective
and volume/weight-effective green energy harvesting [1-5]. Currently, indium tin oxide (ITO) has been used as
the transparent anode for OPV devices because of its excellent optical transparency in the visible range and acceptable
electrical conductivity