Influence of Ionic Liquid Electrolytes on the Photovoltaic Performance of Dye‐Sensitized Solar Cells

Abstract New binary ionic liquid electrolytes based on 1‐methyl‐1‐butylpyrrolidinium bis(trifluromethylsulfonyl)imide, 1‐butylpyridinium bis(trifluromethylsulfonyl)imide, 1‐methyl‐3‐ethylimidazolium bis(trifluromethylsulfonyl)imide, 1‐methyl‐3‐ethylimidazolium tetracyanoborate, or 1‐methyl‐3‐ethylimidazolium tricyanomethanide coupled with 1‐methyl‐3‐propyl‐imidazolium iodide were developed for dye‐sensitized solar cells (DSCs). We examined these ionic liquid compositions in conjunction in conjunction with a diketopyrrolopyrrole‐based donor‐π bridge acceptor dye (DPP‐13) in dye‐sensitized solar cells and also investigated the influence of adding lithium ions to the electrolyte to enhance the device performance. The best device exhibited a short‐circuit current density of 15.2 mA cm −2 , an open‐circuit voltage of 678 mV, and a fill factor of 71 %, corresponding to an overall power conversion efficiency (PCE) of 7.1 % under standard AM 1.5G illumination at 100 mW cm −2 .