The objective of this work is to investigate the performance of chlorophyll sensitized solar cells (CSSCs) with gel electrolyte based on polyvinyl alcohol (PVA) with single iodide salt (potassium iodide (KI)) and double salt (KI and tetrapropylammonium iodide (TPAI)). Chlorophyll was extracted from the bryophyteHyophila involuta. The CSSC with electrolyte containing only KI salt produced a short circuit current density (Jsc) of 4.59 mA cm−2, open circuit voltage (Voc) of 0.61 V, fill factor (FF) of 0.64, and efficiency (η) of 1.77%. However, the CSSC with double salt electrolyte exhibitedJscof 5.96 mA cm−2,Vocof 0.58 V, fill factor FF of 0.58, andηof 2.00%. Since CSSC with double salt electrolyte showed better efficiency, other cells fabricated will use the double salt electrolyte. On addition of 0.7 M tetrabutyl pyridine (TBP) to the double salt electrolyte, the cell’s efficiency increased to 2.17%,Jsc=5.37 mA cm−2,Voc=0.55 V, and FF = 0.73. With 5 mM chenodeoxycholic acid (CDCA) added to the chlorophyll, the light to electricity efficiency increased to 2.62% withJscof 8.44 mA cm−2,Vocof 0.54 V, and FF of 0.58.

Phthaloylchitosan-based gel polymer electrolytes were prepared with tetrapropylammonium iodide, Pr4NI, as the salt and optimized for conductivity. The electrolyte with the composition of 15.7 wt.% phthaloylchitosan, 31.7 wt.% ethylene carbonate (EC), 3.17 wt.% propylene carbonate (PC), 19.0 wt.% of Pr4NI, and 1.9 wt.% iodine exhibits the highest room temperature ionic conductivity of 5.27 × 10−3 S cm−1. The dye-sensitized solar cell (DSSC) fabricated with this electrolyte exhibits an efficiency of 3.5% withJSCof 7.38 mA cm−2,VOCof 0.72 V, and fill factor of 0.66. When various amounts of lithium iodide (LiI) were added to the optimized gel electrolyte, the overall conductivity is observed to decrease. However, the efficiency of the DSSC increases to a maximum value of 3.71% when salt ratio of Pr4NI : LiI is 2 : 1. This cell hasJSC,VOCand fill factor of 7.25 mA cm−2, 0.77 V and 0.67, respectively.

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.

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The molecular optimisation strategies exhibit ultrahigh Seebeck coefficient through a six-pronged approach to maximise entropy during the transition from low spin (LS) to high spin (HS).