Fig. 3: Photophysical characterization of 4-PP-, 4,4-BP-, and 1,4-DPB-doped SiO2 MPs.
From: Matrix-induced defects and molecular doping in the afterglow of SiO2 microparticles
a Long-lived emission profiles of 4-PP-doped SiO2 MPs at varying temperatures. Note that the profile of 297 K listed below the profile of 673 K (Low panel) shows the afterglow profile obtained by repeating the measurement at 297 K after cooling down from 673 K. For obtaining the long-lived emissions, the delay time was fixed at 2 ms. b Cyan afterglow lifetime of 4-PP-doped SiO2 MPs as a function of excitation wavelength and temperature. c, d Short- (upper panel) and long-lived (lower panel) emission profiles of 4,4-BP-doped SiO2 MPs and 1,4-DPB-doped SiO2 MPs under different excitation wavelengths. Note that the delay time was fixed at 2 ms for obtaining the long-lived emission profiles. e, f Blue afterglow lifetime of 4,4-BP-doped SiO2 MPs and green afterglow lifetime of 1,4-DPB-doped SiO2 MPs as a function of excitation wavelength. g, h Luminescence photographs illustrating aqueous dispersions of 4,4-BP-doped SiO2 MPs and 1,4-DPB-doped SiO2 MPs upon ceasing excitation at different wavelengths.
