Energy spectra of dyes embedded in SiO2 sol-gel glass

Dyes, which are commonly used in the food industry, were incorporated at tw o different concentrations into SiO2 coatings prepared using the sol-gel me thod. The optical absorption, the excitation and emission spectra of the co lored glass coatings were used to characterize the optical transitions in t he UV-Vis region. The results reveal the existence of discrete energy level s in the systems studied. A simple quantum mechanical model is presented tr eating the organic molecules as two-dimensional potential wells for electro ns. The analysis made give a reasonable agreement with the experimental opt ical transitions determined from absorption and emission spectra.