Effect of the matrix on the radiative lifetimes of rare earth doped nanoparticles embedded in matrices

The radiative lifetimes, tau (R). of the excited states of rare earth (RE) ions contained in nanocrystalline insulators are different compared to their values in crystallographically equivalent bulk crystals. Their lifetimes depend on the effective index of refraction of the media consisting of nanoparticles and the substance filling the space between them. Here, the radiative rates are studied as a function of particle size and the amorphous matrices containing the nanoparticles. Effects due to the effective index of refraction and site distortions associated with the increased inhomogeneous broadening are observed. (C), 2001 Elsevier Science B.V. All rights reserved.