Nanosized semiconductor particles in glasses prepared by the sol-gel method: their optical properties and potential uses

The nanometer-sized semiconductor crystallites of CdS, CdSe, CdTe, and PbS were formed by chemical procedure in glass films prepared by the sol-gel method. The films are either pure silica, silica ormosils, zirconia or combined zirconia with ormosils. As the sizes of the nanocrystallites decrease, controlled by the preparation method, the band gap shifts to higher energies due to the quantum size effect. Spectroscopic methods of absorption and luminescence allow to determine the shift and atomic force microscopy (AFM) and transmission electron microscopy (TEM) the size of the nanoparticles. X-Ray diffraction for larger nanoparticles provides information on the crystallographic structure of the particles. The potential of the nanocrystallites embedded in glass films in nonlinear optics and electrooptic devices is discussed. (C) 2002 Elsevier Science B.V. All rights reserved.