Confined nucleation and growth of organic nanocrystals in sol–gel matrices

Abstract

We have engineered new hybrid organic–inorganic materials through a simple and generic preparation of stable organic nanocrystals grown in gel–glass matrices. This process was based on confined nucleation and growth of dyes in the pores of dense gels. For bulk samples, narrow size distributions of particles were obtained between 10 and 20 nm in diameter. We extended this method to the preparation of organic nanocrystals embedded in sol–gel thin films by spin-coating. For all these nanocomposite samples, we significantly increased the dye stability and obtained promising optical properties (luminescence, NLO properties, SHG). Moreover we also demonstrated the basic working principles of a new type of fluorescent nanosensors through the preparation of organic luminescent nanocrystals grown in silicate films.