Dye-sensitized solar cell using extract from petals of male flowers Luffa cylindrica L. as a natural sensitizer

• Natural plant pigments as sensitizer for dye-sensitized solar cell (DSSC).
• Dye extracted from petals of male flowers Luffa cylindrica L. used as sensitizer for TiO2 based DSSC.
• Incident photo-to-current conversion efficiencies (IPCE) ∼30%.
• Economically more viable solar energy conversion device.

The study reports use of natural dye extracted from petals of male flowers Luffa cylindrica L. as sensitizer for TiO2 based dye-sensitized solar cells. Optical characteristics of the dye extract and photoelectrochemical performance of the cells were studied. The extracts showed the UV–Vis absorptions in the 400–450 nm range with broad maxima at ∼430 nm. FTIR spectra of extract revealed the presence of anchoring groups and coloring constituents. DSSC was fabricated using natural dye loaded TiO2 photoelectrode, electrolyte containing I−/I3− redox mediator and Pt counter electrode by assembling them into a cell module. Conversion of solar light into electricity was successfully accomplished and DSSC based on petals of male flowers Luffa cylindrica L. extract exhibited an open-circuit voltage (Voc) of 0.52 V, short-circuit current density (Jsc) of 0.44 mA cm−2, Pmax 130 μW, fill factor (FF) of 0.60, conversion efficiency of 0.13% and IPCE ∼30% (at λ = 430 nm).