Size dependent effect of electron-hole recombination of CdS quantum dots on emission of Dy^sup 3+^ ions in boro-silicate glasses through energy transfer

The glass system SiO2-B2O3-ZnO-Na2O-K22O-CdS with addition of Dy3+ ions was synthesized by using conventional mdt-quench method. The CdS quantum dots in a glass matrix was studied using optimized heat treatment schedule. The growth of quantum dots was confirmed by optical absorption (UV-Vis), X- ray diffraction (XRD) and High resolution transmission electron microscopy (HRTEM). The optical absorption and luminescence were studied for these glasses. The photoluminescence spectra shows energy transfer between CdS quantum dots and Dy3+ ions. Because of quantum confinement, CdS QDs emits light as a result of electron hole recombination and some energy is transferred to nearest energy level of the Dy3+ ions to give combined emission due to recombination of electron-hole and electronic transitions (i.e. 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2) of Dy3+ ions.