Photovoltaic properties of Cassia fistula flower extract based dye-sensitized solar cells

The possibility of the use of dye extract from the petals of Cassia fistula flowers as natural dye sensitizers for dye-sensitized solar cells (DSSCs) is explored. To analyze the potential of the sensitizers, characterization by methods like current–voltage response, cyclic voltammetry, and electrochemical impedance spectroscopy were utilized. Surface morphology of the TiO₂ film was studied by atomic force microscopy and scanning electron microscopy. Fourier-transform infrared spectroscopy was used to determine the functional groups present in the dye extract. Device sensitized with ethanolic extract of the flower showed maximum photovoltaic conversion efficiency of 0.182%. The acidified water extract-based device showed an enhanced efficiency of 0.125% compared with that based on pure water extract. We discuss the uncomplicated method of extraction of flower pigments and their execution in DSSCs.