Highly luminescent CdSe nanoparticles embedded in silica thin films

Thin films of luminescent CdSe nanoparticles with and without silica capping were prepared using sol-gel method. The blue shift observed in the optical absorption spectra suggested quantum confinement effect in the prepared films. The films showed photoluminescence emission in the range of 510-590 nm depending upon the particle size of CdSe particles. The emission intensity increased when CdSe particles were embedded in silica matrix. The emission intensity was found to decrease with aging for the films containing CdSe particles without silica capping when they were exposed in relatively humid air (relative humidity 80%). The films containing CdSe nanoparticles embedded in silica matrix showed more stable behavior. The emission intensity practically remained constant with aging in humid atmosphere.