Dye-Sensitized Solar Cell Using Natural Dyes Extracted From Dried Flowers

Abstract

In this thesis, dye sensitized solar cells (DSSCs) were prepared using titanium dioxide (TiO2) as a semiconducting layer spread on transparent conducting fluorine tin oxide (FTO) coated glass using doctor blade method and based on three natural dyes extracted from Hibiscus Rosa Sinensis, Hibiscus Sabdariffa and Rosa Damascena flowers as sensitizers. Three processes were conducted to improve the performance of prepared solar cells namely pre and post-treatment of TiO2 and FTO layers with three acids, changing the pH of the extract solution, and capping TiO2 particles with ZnO layer. Many measurements were conducted on all DSSCs such as UV-Vis absorption spectra in the range of 400 nm to 800 nm of all dyes, J-V characteristic curves under 100 mW/cm2 illumination, and impedance spectroscopy under dark and illumination. Many of the photovoltaic parameters of the cells were presented. The best performance was obtained for the DSSC sensitized with Hibiscus Sabdariffa dye solution without treatment with Jsc of 1.18 mA/cm², Voc of 0.46 V, FF of 0.51, and an efficiency η of 0.28%. When the treatment processes were applied to DSSC sensitized with Hibiscus Sabdariffa, the efficiency was lowered for all treatments. The treatment of the dye solution of Hibiscus Rosa Sinensis with hydrochloric acid to get pH of 2.0 showed an efficiency improvement of 400%.