Sol–gel synthesis and photoluminescence properties of spherical SiO₂@LaPO₄:Ce³⁺/Tb³⁺particles with a core–shell structure

Abstract

LaPO4:Ce3+ and LaPO4:Ce3+, Tb3+ phosphor layers have been deposited successfully on monodispersed and spherical SiO2 particles of different sizes (300, 500, 900 and 1200 nm) through a sol–gel process, resulting in the formation of core–shell structured SiO2@LaPO4:Ce3+/Tb3+ particles. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microcopy (SEM), transmission electron microscopy (TEM), and general and time-resolved photoluminescence (PL) spectra as well as lifetimes were used to characterize the resulting SiO2@LaPO4:Ce3+/Tb3+ samples. The XRD results demonstrate that the LaPO4:Ce3+, Tb3+ layers begin to crystallize on the SiO2 templates after annealing at 700 °C, and the crystallinity increases on raising the annealing temperature. The obtained core–shell phosphors have perfectly spherical shape with a narrow size distribution, non-agglomeration, and a smooth surface. The doped rare-earth ions show their characteristic emission in the core–shell phosphors, i.e. Ce3+ 5d–4f and Tb3+ 5D4–7FJ (J = 6–3) transitions, respectively. The PL intensity of the Tb3+ increased on increasing the annealing temperature and the SiO2 core particle size. The energy transfer process from Ce3+ to Tb3+ in SiO2@LaPO4:Ce3+, Tb3+ core–shell particles was studied using the time-resolved emission spectra.

Controllable Synthesis and Luminescence Properties of La(OH)3 and La(OH)3:Tb3+ Nanocrystals with Multiform Morphologies

“…[36][37][38][39] The excitation spectrum of the La(OH) 3 :Tb 3+ nanowires (Figure 5a) is composed of a broad band centered at 240 nm and some sharp bands in the region from 275 to 400 nm. The broad band and small peaks at 275 and 289 nm are ascribed to the spin-allowed and spin-forbidden interconfigurational 4f…”

“…The result is basically in agreement with other Tb 3+ -doped phosphors in previous reports. [37,44,45] The CL properties of the as-obtained La(OH) 3 :2 %Tb 3+ phosphors were also investigated. Figure 7 shows typical CL spectra of the La(OH) 3 :Tb 3+ nanowires and short nanoprisms under the excitation of an electron beam (accelerating voltage = 3 kV; filament current = 98 mA).…”

Facile Synthesis and Photoluminescence of Europium Ion Doped LaF3 Nanodisks

“…It is well-known that a large www.eurjic.orgparticle size is helpful for improving the PL intensity of phosphors. [47,48] A more extensive investigation of the differences in the luminescent properties of the products with different morphologies, crystal structures, sizes, and dimensions will be further investigated in our future work. …”

Study on Ce‐Doped Nonstoichiometric Nanosilica for Promoting Properties of Polysulfone Membranes

“…As is well known, rare earth elements have been widely applied in various materials as effective doping agents [9][10][11]. For example, Fan et al [12] prepared Ce-doped TiO 2 nano-powders through the sol-gel process.…”