Electrochemical and photovoltaic study of sunset yellow and tartrazine dyes

摘要

Two commercial dyes, sunset yellow and tartrazine, were electrochemically investigated on graphite electrode by employing cyclic voltammetry, differential pulse voltammetry, and square wave voltammetry techniques. Both dyes undergo one electron oxidation in the potential range of 0.3-1.2 V. The optical parameters such as lambda (max), lambda (onset), and epsilon were determined from UV-Vis spectroscopy. To assess their ability as sensitizers for dye-sensitized solar cells, their HOMO/LUMO energies were determined by cyclic voltammetry and UV-Vis spectroscopy. The energy gap was found 2.12 and 2.33 eV for sunset yellow and tartrazine, respectively. Density functional theory was used for frontier molecular orbital calculations. The dyes were tested for their photovoltaic performance using electrochemically deposited ZnO thin film semiconductor on conducting glass. Electrochemical impedance spectroscopy was employed to investigate the charge transfer and the charge recombination processes occurring within the cell.