Effect of Doping Anions’ Structures on Poly(3,4-ethylenedioxythiophene) as Hole Conductors in Solid-State Dye-Sensitized Solar Cells

Poly(3,4-ethylenedioxythiophene) with different doping anions as hole conductors was investigated in solid-state dye-sensitized solar cells (DSC). The different perfluoroalkyl chains of bis(perfluorosulfonyl)imides (N(C n F 2 n +1 SO 2 ) 2 − ) or perfluorosulfonates (C n F 2 n +1 SO 3 − ) were selected as doping anions in this study. Photoelectrochemical measurements reveal that the perfluoroalkyl chain in the doping anions plays an important role in the performance of PEDOT-based DSCs. This study presents a broader way to find PEDOT with good hole conductivity through changing doping anions’ structures. In addition, in the case of perfluorosulfonates, the appropriate perfluoroalkyl chain will improve the performance of the cell. Cyclic voltammetry (CV) and high oxidation potential stability testing indicate that N(C n F 2 n +1 SO 2 ) 2 − are more suitable as doping anions in PEDOT hole conductors in solid-state DSC.