Fig. 1: Interactions between molecule dopants and intrinsic defects in SiO2 matrix.
From: Matrix-induced defects and molecular doping in the afterglow of SiO2 microparticles
a Schematic depiction of the matrix structure of molecule-doped SiO2. b Schematic illustration of energy transfer between molecule dopants and SiO2 defects in both singlet and triplet states. c Short- (upper panel) and long-lived (lower panel) emission profiles of SiO2 MPs under various excitation wavelengths at 77 K. The excitation wavelength was increased from 240 (navy) to 350 (darkred) nm. The delay time was set at 2 ms for obtaining the long-lived emissions. It is noteworthy that SiO2 MPs were prepared using a modified Stöber method, followed by hydrothermal treatment at 180 °C for 3 h. d Optical absorption band of the as-prepared SiO2 MPs in the extreme UV spectral region. e ESR spectra of the as-prepared SiO2 MPs measured under different conditions.
