Effect of HAc treatment on an open-environment prepared organic redox couple based on hydroquinone/benzoquinone and its application in dye-sensitized solar cells

A facile and reliable method is applied to prepare the electrolyte based on hydroquinone (HQ)/benzoquinone (BQ) redox couple for dye-sensitized solar cells (DSSCs) in open environment by adding moderate amount of acetic acid (HAc), and the best conversion efficiency (η) of 5.82% is achieved under 100 mW cm−2 (AM 1.5 G) illumination. Electrochemistry properties of DSSCs using such redox couple are measured and the results show a higher current and better charge transfer in contrast to I−/I3−. And a slightly higher efficiency of 5.88% is obtained when HQ and BQ are symmetrically substituted by two methyls. With advantages of high efficiency, compatible with the most common dye N719 and easily tuned by facile structural modification, the redox shuttle employing HQ/BQ via HAc treatment is very promising to be employed in efficient DSSCs.