Iodine vapor doped polyaniline nanoparticles counter electrodes for dye-sensitized solar cells

In this study, we demonstrated the enhanced efficiency of dye-sensitized solar cells (DSSCs) using iodine vapor-doped nanostructured polyaniline (PANI)-based counter electrodes (CEs). The electrical conductivities of chemically synthesized PANI emeraldine salt (PANI-ES) and dedoped emeraldine base (PANI-EB) were increased from 3.1 S cm(-1) to 9.3 S cm(-1) and 2.0 x 10(-5) S cm(-1) to 0.5S cm(-1), and the doping levels of those were increased from 38.2% to 41.8% and 3.2% to 33.3%, respectively, via iodine vapor doping. Compared with PANI-ES and PANI-EB CEs, iodine-doped PANIs (PANI-ES-I-2 and PANI-EB-I-2) CEs with improved electrical properties were demonstrated higher electro-catalytic activity toward I-/I-3(-) redox couples, due to better charge carrier transport and reduced charge transfer resistance. The cells based on the PANI-ES-I-2 and PANI-EB-I-2 CE exhibited higher photovoltaic parameters and efficiency. Moreover, we successfully increased the cell efficiency of the PANI-ES-I-2 CE-based DSSCs to a maximum efficiency of similar to 7.86%. (C) 2013 Elsevier B.V. All rights reserved.