Photostability of Ponceau 2R Doped Thin Film Sol-Gel Silica as Luminescent Solar Collector

Problem statement: Current researches had shown that the photostability of a luminescent solar collector depend on the method of its preparation and type of using dye. This research therefore aimed at studying the stability of luminescent solar collector prepared by sol-gel spin coating method using Ponceau 2R. Approach: The effect of silica matrix on the photostability and fluorescence properties of Ponceau 2R was investigated in terms of concentration using absorption and emission techniques. The photostability of Ponceau 2R doped sol-gel samples was also examined through 60 days exposure to sunlight. Results: The dye in the solid matrix had absorption and emission characteristics different from those in the liquid solution. The transition energy for electrons were direct allowed transition for all examined concentrations and there is no variation in the values of optical gap Energy (E_g) by increasing the dye content or exposure times. The dependence of the width of the tails of the localized states in the band gap (E_u) on the concentration and exposure times were also studied. The emission spectra for the samples before and after exposure to sunlight showed that the sample of concentration 0.1 wt% had the highest fluorescent intensity and fluorescence quantum yield. Conclusion/Recommendations: This study showed that Ponceau 2R of 0.1 wt% concentration has a good potential for application in a luminescent solar collector using sol-gel techniques.