Formation of Luminescent CdTe–Silica Nanoparticles through an Inverse Microemulsion Technique

CdTe quantum dots (QDs, 3–6 nm(phi)) were incorporated into silica nanoparticles (20–30 nm(phi)) by an inverse microemulsion technique. The transmission electron microscope image shows that the QDs are situated on the surface of silica particles. These QD-silica particles in solution exhibited a stable luminescence with at least the similar quantum efficiency (ca. 5%) as that of the initial colloidal solution over several weeks of storage. The particles taken out from the solution as a powder form showed the same quantum efficiency for a long time as well. This is because silica acts as an effective protective environment for the QDs.