Comparative Analysis of Characteristics of Dye-Sensitized Solar Cells Utilizing Extracts of Young vs Mature Leaves of Elaeocarpus Serratus as Natural Sensitizers

Abstract

This study addresses the pressing global need for sustainable energy sources by exploring dyesensitized solar cells (DSSCs) as a viable alternative. Specifically, the research focuses on extracting natural pigments from Elaeocarpus serratus (Sri Lankan olive) leaves to enhance the efficiency of DSSCs. These leaves undergo color changes as they mature, presenting opportunities to extract different types of pigments at different ages. Extraction involves boiling pieces of leaves in absolute ethanol to obtain the desired pigments. Further characterization via UV-visible spectroscopy revealed the presence of different absorption bands of pigments in the natural dyes’ extracts. The constructed DSSCs employed these natural dyes, coated on TiO2 films deposited on FTO glass plates as the photoanodes. The liquid electrolyte was I2/I3 - and a platinum-sputtered glass plate served as the counter electrode. Photovoltaic characteristics were evaluated using a computerized PK-IV 100 I-V analyzer under 100 W/m2 illumination. Results indicated the superior performance of DSSCs utilizing young leaf extracts, yielding a short circuit current density (JSC) of 3.950 mA/cm2, open circuit voltage (VOC) of 458.8 mV, and a fill factor (ff) of approximately 0.553 with an efficiency (η) of 1.003%. Conversely, DSSCs utilizing. Mature green leaf extracts exhibited lower performance metrics, with JSC of 2.379 mA/cm2, VOC of 477.5 mV, ff around 0.492, and η of 0.559%. Therefore, the efficiency of DSSC fabricated with young leaf is 56% higher than the DSSC made with mature green leaf extract.