Effect of bandgap energies by various color petals of Gerbera jamesonii flower dyes as a photosensitizer on enhancing the efficiency of dye-sensitized solar cells

The photovoltaic solar cell is a complementary source of energy, being a solution for energy generation. The Grätzel cells or dye-sensitized solar cells (DSSCs) represent a substitute for silicon-based solar cells that are interesting owing to their low-cost manufacturing, non-toxicity with a good recovery efficiency. Herein, the novel natural dyes containing luteolin molecules were prepared by four specimens of Gerbera jamesonii flowers with different colors of petals such as coral, orange, red and yellow. The light absorption characteristics and the presence of functional groups of extracted dyes were recognized by Ultraviolet–Visible (UV–Vis) spectroscopy and Fourier transformed infrared (FTIR) spectroscopy, respectively. The energy bandgap of the extracted dyes has been investigated by UV–Vis and Tauc relation. In addition, DSSCs were constructed via newly extracted dye adsorbed nanosized titanium dioxide (TiO 2 ) as a photoanode, nanostructured platinum as a photocathode and redox electrolyte. The photoanodes and photocathodes surface roughness was analyzed by atomic force microscope (AFM). Further, the morphologies of photoanodes and photocathodes are characterized by field scanning electron microscope (FESEM). The photovoltaic performances were carried out to recognize the influences of the photoanodes and the interactions with different G. jamesonii flowers dye extract molecules on the overall cells efficiency. The photoelectrochemical properties for instance open-circuit voltages ( V oc ), short-circuit photocurrent densities ( J sc ), fill factors (FF), and efficiency of energy conversion ( η ) were also investigated. The maximum power conversion efficiency of the cell has reached 1.54%, thus obtaining an excellent value when compared with the literature for different concentrations of flavonoids and showing the great potential of these flowers in the application of solar cells sensitized by natural dyes.