During the last 50 years, there has been a considerable amount of work for the elaboration of efficient luminescent materials, most of them dealing with the search for new chemical compositions. Only a very few studies have concerned the study of the influence of the microstructure of the materials on their properties of emission, especially when the grain sizes of the materials are in the nanometer range. On another side, important advances have been performed in colloid chemistry in the last years, especially in the case of II-VI chalcogenides, as a consequence on the intense activity around the physics of quantum confinement in semiconductors.
The basic idea of this work is to show that the techniques developed in the case of II-VI nanoparticles could find interesting applications for the elaboration of nanostructured luminescent materials. This is first illustrated in the case of pure CdS nanoparticles, whose properties are deeply affected by their surface state and their chemical environment. Incorporation of manganese in solid solution in the CdS particles drastically changes the emission process, which now essentially depends on the manganese content inside each particle. Finally, the extension of the synthesis process to rare earth doped oxide particles is presented, and the luminescence efficiency is discussed as a function of the size, the structure, and the chemical environment of the particles.