Polyaniline porous counter-electrodes for high performance dye-sensitized solar cells

Porous polyaniline-camphorsulfonic acid (PANI-CSA) counter-electrodes (CEs) for dye-sensitized solar cells (DSSCs) were fabricated by secondary doping-based polymerization with different porogen decomposition. The average pore diameter was ca. 50 and 150 nm for BPO and AIBN, respectively. The increased Brunauer-Emmett-Teller (BET) surface area of porous PANI-CSA CEs facilitated facile electron exchange between the CEs and the redox electrolyte, resulting in higher electro-catalytic performance than that of Pt-coated indium-doped tin oxide (ITO) CE. The porous PANI-CSA nanostructures with increased BET surface area exhibited an equivalent incident photon-to-electron conversion efficiency (IPCE) of 68.86% and a power-conversion efficiency (PCE, eta) of 6.23% compared to DSSCs containing Pt-coated ITO CE (IPCE of 68.70% and eta = 6.17%). It is noteworthy that the performance of DSSCs with porous PANI-CSA CEs represented a 101.0% relative efficiency compared to Pt-coated CEs.