Photovoltaic Performance of Porphyrin-Based Dye-Sensitized Solar Cells with Binary Ionic Liquid Electrolytes

Herein, green porphyrin sensitizer Y350-based dye-sensitized solar cells (DSCs) with binary ionic liquid-based electrolytes are studied, which are a mixture of 1-methyl-3-propyl-imidazolium iodide and 1-methyl-1-butylpyrrolidinium bis(trifluromethylsulfonyl) -imide, 1-butylpyridinium bis(trifluromethylsulfonyl)imide, 1-methyl-3-ethylimidazolium bis(trifluromethylsulfonyl)imide, or 1-methyl-3-ethylimidazolium tetracyanoborate. The best semitransparent green DSC device exhibits a short-circuit photocurrent density of 9.1 mA cm(-2), an open-circuit photovoltage of 727 mV, and a fill factor of 70%, corresponding to an overall power conversion efficiency (PCE) of 4.9% under standard AM 1.5G illuminations at 100 mW cm(-2). The PCE increases to 6.1% with opaque films containing larger light-scattering TiO2 particles.