MITRAGYNA SPECIOSA DYE SENSITISER AS THE LIGHT-HARVESTING MOLECULES FOR DYE-SENSITISED SOLAR CELLS

Abstract

In this study, natural dye sensitisers derived from ketum (Mitragyna speciosa-MS), spinach (Spinacia oleracea-SO), curry (Murraya koenigii-MK), papaya (Carica papaya-CP), and henna (Lawsonia inermis-LI) were investigated for dye-sensitised solar cells (DSSCs). Ultraviolet-Visible Spectroscopy (UV-Vis), Fourier Transform Infrared spectroscopy (FTIR), Open-Circuit Voltage Decay (OCVD) and Current to Voltage (I-V) were used to analyse the natural dye and the fabricated DSSC. It was observed that all dye solutions contain the majority of important functional groups of chlorophyll-based sensitisers, which is crucial for the dye-to-TiO2 (Titanium (II) Oxide) attachment, making them suitable sources of energy harvesting pigments. In this regard, the dye pH and chemical bonding of the respective dyes play a significant role that contribute to the overall performance of the DSSCs. It was discovered that a dye based on MK provided the best DSSC performance. This is because MK-based dye has higher content of functional groups, an optimal pH, and the slowest properties of back electron recombination among the OCVD measurements. Because of the combination of these properties, the open-circuit voltage (VOC), short-circuit current density (JSC), and power conversion efficiency (PCE) values have been determined to be 0.58 V, 2.48 mA/cm2, and 0.47%, respectively.