Utilization of natural dyes extracted from mustard flower (Genus: Brassica, Species: Napus) as photosensitizer for DSSC: Experimental and computational studies

Abstract

Dye-sensitized solar cells (DSSC) are considered as one of the most promising photovoltaic technologies, while exploring alternatives to traditional silicon-based solar cells. Dye sensitizer is a very important component of DSSC and the use of natural dyes in these cells is a promising development for this technology, as it has non-hazardous impact on the environment. This work reports the new natural dye extracted from Brassica Napus flower petals and used as sensitizer in TiO₂ based DSSC. UV–Vis spectra showed the presence of carotenoid and flavonoid pigments along with broad absorption in dye loaded TiO₂. FITR revealed functional groups in the Brassica Napus dye extract. Mass spectroscopy was used to find major constituents present in extract. With the natural Brassica Napus sensitizer and TiO₂, photovoltaic performance results viz. conversion efficiency (ɳ%) 0.062, short circuit current density (J_sc) 0.45 mA/cm², open circuit voltage (V_oc) 0.260 V and fill factor (FF) 0.52 were observed. Further, HOMO-LUMO levels of constituents present in Brassica Napus have been measured via CV measurements and compared with relative energetic obtained by computational studies. The transport characteristics revealed from EIS studies were used to rationalize the observed photo-voltaic performance of the DSSC.