Chlorophyll as sensitizer in I−/I3−-based solar cells with quasi-solid-state electrolytes

Abstract

The performance of chlorophyll dye-sensitized solar cells (DSSCs) with quasi-solid-state polyacrylonitrile (PAN)-based iodide electrolytes has been investigated. The iodide ion-supplying salt used is tetrapropylammonium iodide (TPAI). Chlorophyll is extracted from a species of the moss bryophyte that can be found on rocky surfaces. The DSSC with electrolyte having the composition 9.9 wt% PAN–39 wt% ethylene carbonate–39.7 wt% propylene carbonate–9.9 wt% TPAI–0.8 wt.% iodine produces the highest efficiency of ( η) 1.97% with a short-circuit current density ( Jsc) of 5.78 mA cm−2, open circuit voltage ( Voc) of 0.60 V, and fill factor (FF) of 0.57. The incident photon-to-current efficiency curves follow the current density–voltage characteristics with the DSSC using the above electrolyte exhibiting the highest power conversion at 339 nm. The sensitizer and gel polymer electrolyte play an important role in determining the performance of the DSSC.