Fabrication of Dye-Sensitized Solar Cells using natural flower dye extracts: A study on performance analysis and solar dye degradation

The performance of dye-sensitized solar cell (DSSC) mostly depends on dye as the sensitizer material. Natural dyes can be used as a suitable alternative, because of its minimal extraction effort, easy attainability, and no environmental risk. The absorption spectrum of the extracted dyes was observed by using UV-Vis spectrometer, which ensued a peak value around 490–550 nm. In this study, three flowers such as Cape honeysuckle (Tecomaria capensis), Bauhinia (Bauhinia purpurea) and Kalanchoe (Kalanchoe blossfeldiana) were used as the sensitizer. The absorption coefficient (α) and optical energy band gap of the extracted dyes were calculated. The extracted dyes were examined for the degradation study under sunlight and observed a faster degradation rate for the dye extracted from Tecomaria capensis. Functional groups and intermolecular bonds were identified by using FTIR spectroscopy. The J-V curves of the assembled solar cell beneath Air Mass 1.5 utilizing a simulated illumination of 100 mW/cm2 were plotted. The assembled solar cell using Kalanchoe flower dye as the sensitizer shows the best performance among the three dyes with a short-circuit current density (Jsc) of 2.874 mA/cm2, open-circuit voltage (Voc) of 0.712 V and a noticeable power conversion efficiency (PCE) of 0.610%. From the stability studies, the cell comprises Kalanchoe flower dye showed more stable under natural conditions.