Investigation of the two-dimensional quantum wells made by the dye incorporation into the SiO2 sol-gel glass

SiO₂ thin colored films were produced by the solution-gelatinization technique with addition of organic colorants to the initial solution. Colorants made for the food industry (in particular, Brilliant Black, Rhodamine 6GDN and red No. 3 or erythrozine) were used in the powder form; to influence the size of the powder grains, special mechanical treatment (ball-milling) of the solution was performed. All types of the material obtained reveal an efficient photoluminescence in visible and near infrared parts of the spectrum. We found that each of the systems made possesses a definite set of discrete energy levels, which is determined by the structure of the colorant molecules; besides, the efficiency of the light absorption and emission as well as the light stability of color are affected by the mechanical treatment mentioned above. A quantum mechanical description of the systems studied was attempted, treating the organic molecules as the two-dimensional quantum wells; it shows a reasonable agrement with experiment