Counter electrodes from double-layered polyaniline nanostructures for dye-sensitized solar cell applications

Counter electrodes from polypyrrole (PPy) and polyaniline (PANi) nanostructures were fabricated by chemical and electrochemical approaches for dye-sensitized solar cell (DSSC) applications. It was found that double-layered PANi consisting of a nanoparticle layer and a nanofiber layer was formed by an electrodeposition route, given significantly increased active sites and solar cell performances. The solar-to-electricity conversion efficiency of the double-layered PANi-based DSSC was 6.58% under 100 mW cm−2 (AM 1.5), which was much higher than those of PPy and chemically deposited PANi or Pt-based DSSCs. The enhancement in the conversion efficiency was due to the design of double-layered nanostructures, which resulted in an increased charge transfer kinetics and higher electrocatalytic activity for the I−/I3− redox reaction.