Efficiency Enhanced by Chelation of Al3+ Metal Ions with Erythrina Fusca Flower Dye Harnessing Bathochromic Shift

Abstract

Utilization of natural dyes in dye-sensitized solar cells (DSSCs) presents a sustainable approach towards enhancing photovoltaic efficiency. This study explores the bathochromic shift exhibited by Erythrina fusca (Erabodu) flower dye upon chelation with Al3+ ions, offering an innovative strategy for improving DSSC performance. 20g of chopped flower petals was boiled with 50ml of ethanol until flower petals become pale in colour in the dye extraction process. After that, 0.1 M, AlCl3 solution was added dropwise to 2ml of dye solution until the colour changed to purple. The pH value of Erabadu bare dye was recorded as 5.47 and with the Al3+ ion addition it was changed to 4.49. Through spectroscopic analysis and electrochemical characterization, the chelation mechanism and its impact on dye absorption spectra and electron transfer dynamics was elucidated. The Dye was coated on a thin film of TiO2 nanoparticles deposited on fluorine-doped tin oxide (FTO) glass plates. FTO glass which coated with platinum was used as the counter electrode and iodin/triiodide (I2 / I3 -) was used as the electrolyte. Solar cell was tested with a light source with an intensity of 100 mW/cm2. Al3+ ion chelated Erabadu dye exhibited higher efficiencies than bare dye which was 1.627%. The open circuit voltage (Voc) of this cell was 470mV, short circuit current density (Jsc) was 4.00 mA/cm2 and the fill factor of DSSC’s was 0.553. The Incident Photon to Current Conversion Efficiency (IPCE) of the cell further revealed the action spectrum was broadened between 300 nm – 500 nm enhancing the efficiency. Our findings unveil the potential of Al3+ ion chelated Erythrina fusca dye as a promising sensitizer for DSSCs, paving the way for eco-friendly and efficient solar energy conversion.