A photonic material comprising a core and an envelope is provided for use
in telecommunications, diagnostics, imaging and other applications. In
its simplest form, the core comprises at least one nanoparticle. The
nanoparticle comprises an inorganic material and at least one luminescent
ion, wherein the inorganic material is suitably selected to bind the
luminescent ion. The envelope comprises a suitably selected organic
stabilizing layer that overlays the core. The core and envelope may have
a shell located between them.