Lanthanide doped ZnS quantum dots dispersed in silica glasses: an easyone pot sol–gel synthesis for obtaining novel photonic materials

摘要

Silica glasses containing both ZnS quantum dots (QDs) and luminescent lanthanide ions are attractivecandidates to develop new lighting displays, sensor devices or laser emitters. This work reports an easysol–gel method to prepare Eu3+-doped and Eu3+,Mn2+-codoped ZnS nanocrystals dispersed ina transparent silica matrix. Semiconductor nanocrystals with an average size of 5–6 nm and exhibitingboth cubic and hexagonal phases were obtained at low temperature. The luminescent interactionsbetween ZnS QDs, Eu3+ and Mn2+ ions provided materials with different optical responses but alsogave information about the organization of the different species in the nanocomposite. Indeed, Eu ionswere found to be both dispersed within the silica and located at the surface of the nanochalcogenide, thelatter providing a ZnS/Eu3+ energy transfer. Incorporation of Mn2+ into the ZnS lattice induced theappearance of defect states that enhance the blue luminescence of the nanocomposite. These resultsunderline the sensitivity of optical processes to the nature and organization of the active species, whichis of vital importance for the design of photonic materials