Concentration Dependence of the Photoluminescence Energy and Anisotropy from Dye Molecules and Dye Molecule - Zeolite Composites

Abstract

We analyzed the photoluminescence (PL) peak shift and the anisotropy of dye molecules and dye molecule zeolite composites as function of the concentration of pyronine B (PyB) molecules. We used PyB dye molecules and zeolite L. The PL of PyB molecules was red-shifted with increasing concentration of PyB molecules. However the PL of PyB incorporated zeolite composite was independent of the concentration. The PL intensity anisotropy value also increased with increasing concentration in these composites. The anisotropy of zeolite dye composites was about 2.8 at high concentration; which is close to the theoretical anisotropy value of 3. Since the host zeolite protects dye molecules from aggregation, these results are di erent form the case of dye molecules in a solvent. In addition, we observed the con nement e ect of dye molecule zeolite composites from the blue shift of the PL spectrum.