Optical characterization using nature based dye extracted from hibiscus's flower

Nature has the best way of providing the solution for the next energy harvesting mechanism from fruits plants and flowers. This paper proposes the use of a nature based dye extracted from Hibiscus flower which has potential light absorbing mechanism in dye-sensitized solar cell, an electrochemical oriented solar cell. Ultrasonic extraction treatment was enforced to Hibiscus petals with a temperature, time and frequency rating of 30 °C, 30 minutes and 37 Hz, respectively. Different extracting solvent from ethanol and distilled water were used to observe the absorption spectra by using UV-Vis absorption spectroscopy. Fourier transforms infrared (FT-IR) were used to characterize the functional components of dyes. From FT-IR result, the presence of carbonyl (C=O) and amines group (N-H) represented the existence of betacyaninfrom the betalains group. The result shows that dye extracted under ethanol treatment has the highest absorbance rate compared to extraction by distilled water with the peak of 460 nm. As for the photon energy, results shows a narrow energy gap of 2.70 eV with higher absorption coefficient of 2.35k m^-1 in the visible light spectrum.