Encapsulation viz Capping: Controlled Growth of ZnO Nanophosphor

We reported effective encapsulation and capping of ZnO nanoparticles by using Organic and Inorganic stabilizers. And studied the phenomenon that the intensity of the ultraviolet (UV) photoluminescence (PL) from ZnO was greatly enhanced by incorporating ZnO into the SiO2 matrix as compared to Poly Vinyl Pyrollidone (PVP) capping. PL excitation results show that both the ZnO nanoparticles and the SiO2 matrix in the nanocomposites contribute to the luminescence process for the UV band. ZnO?SiO2 nanocomposite consisting of ZnO nanoparticles embedded in a SiO2 matrix and ZnO capped with Poly Vinyl Pyrollidone both were prepared by the sol?gel technique. Annealing in the range 100-700 deg C in air atmospheres showed high stability of the particle radius due to effective encapsulation within the silica matrix as compared to PVP Capping. Temperature dependent studies shows inorganic encapsulation seemed to be the better than organic capping as it can withstand high temperature, also having much higher luminescence intensity and shows monodispersity of the ZnO nanoparticles. The size of the nanocrystals and nature of their capping, directly influences - Thermal stability, Optical properties, mechanical support and monodispersity which are important parameters for device fabrication. Encapsulation is carried out for increasing persistence time and controlled release of nanoparticles in different environmental conditions.