Enhanced blue photoluminescence from SiCl4-treated nanometer-sized silica particles

We propose a structural model of the blue-light-emitting center in silicon- and silica-based nanostructured materials on the basis of the dehydroxylation reaction of a pair of geminal silanol groups. This model predicts that the blue-light emission can be enhanced by introducing a large amount of surface silanol groups and the appropriate subsequent annealing. This enhancement of the PL emission is indeed observed in nanometer-sized amorphous silica particles with SiCl4.