Photoluminescence and Low-threshold Nonlinear Optical Properties of SiO2 Nanoparticles

The paper reports the study of photoluminescence (PL) of disc- and elliptical-shaped SiO2 nanoparticles exited by photons with energy lower than silica bandgap. Differences in the PL spectra are found to be associated with the structure of the nanoparticle excitonic states of optical electrons.