Three types of site of Mn2+in ZnS:Mn2+nanocrystal/Pyrex glass composites

ZnS:Mn2+ nanocrystals embedded in Pyrex glass matrices have been studied systematically. It has been found by photoluminescence (PL) and excitation (PLE) spectra that doped Mn impurities can be classified as two types, occupying substitutional sites (Mn2+)sub and interstitial sites (Mn2+)int. EPR experiments support this conclusion. In addition, Mn clusters were also identified from the EPR spectra. We observed the increases in the g1 factors and hyperfine structure (HFS) constants with decreasing diameters of the nanocrystals. These increases are due to the hybridization between s-p states of ZnS and d states of the Mn ions by quantum confinement effects and the surface states.