Anomalous Photoluminescence in Silica-Coated Semiconductor Nanocrystals After Heat Treatment

摘要

Methods for preparing emitting semiconductor nanocrystals (NCs) several nm in size have been greatly advanced over the last 20 years.[1–8] The high brightness and wavelength tunability of NCs with one excitation wavelength make them a new type of phosphor especially well-suited for biological tagging.[9,10] These NCs usually require an appropriate matrix to prevent them from deteriorating. Sol–gel derived silica glass is one of the best candidates for such a matrix.[11,12] Other than being used as a protection layer, glass matrices have been used to grow NCs by heating after the constituent ions of the NCs become oversaturated. The glass matrix acts as a distinctive reaction field, having solubility and diffusion constants as much as several orders of magnitude different from those of normal solutions.