Extraction and energy gap determination of various plant dyes using UV-vis analysis for dye-sensitized solar cells

• Main Authors: Bengotchea, Joanna Sheleih Cortez, Wang, Lloyd Heinrich Alejandro
• Format: text
• Language: English
• Published: Animo Repository 2016
• Subjects: Dye plants; Dye-sensitized solar cells; Dyes and dyeing
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/6752
• Institution: De La Salle University

Over the years, many researchers and applications have further revolutionized dye-sensitized solar cells by increasing its efficiency while maintaining its durability and low-cost production. The objectives of the study were to extract natural dyes that can be used for DSSC and to determine which extracted dye obtained the highest absorptivity coefficient and the lowest average onset energy gap, which would be the best candidate to construct the DSSC. The extracted pigments were from beet vegetables, red cabbage, spinach, and strawberry. They were extracted using various methods and solvents. The UV-vis spectrometer was used to analyze the absorbance of the extracted dye samples, while the IR spectrometer was used to determine the common functional groups present in the dye. The best extraction method was concluded to be the spinach boiled in ethanol dye. This method was able to obtain the lowest average Egop onset at 1.814eV and the highest average absorptivity coefficient of 83.307% (w/v) cm1 among all the extracted dyes. The selection of the best plant dye and method were based on its absorptivity coefficient and onset energy gap. A material having a high absorptivity coeficient would result to more photons being absorbed from light and having low onset energy gap would require lesser energy to excite the electrons from the ground state to a higher energy state.