Synthesis, structure and multicolor-tunable luminescence of the dandelion-like SiO2:Ln3+ (Ln = Eu, Tb) nanophosphors

A series of novel color tunable dandelion-like SiO2:Ln3+ (Ln = Eu, Tb) nanophosphors of approximately 70 nm diameter were prepared using a simple hydrothermal route. The phase, time-dependent shape evolution, morphology, sizes, and luminescence properties of the as-prepared products were well characterized by means of X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectrometry, and photoluminescence spectra as well as kinetic decay curves. Under ultraviolet excitation, the Eu3+ and Tb3+ singly doped SiO2 samples showed strong red and green emission, respectively. Furthermore, the luminescence colors of the as-prepared Tb3+, Eu3+ co-doped dandelion-like SiO2 nanophosphors could be altered from green to red, including green-yellow, yellow, orange yellow and reddish orange, by simply adjusting the doping concentrations of Eu3+.