Particle size-related limitations of persistent phosphors based on the doped Y3Al2Ga3O12 system

Abstract

Co-doped Ce3+, Cr3+ and Pr3+ yttrium–aluminium–gallium garnet powders of various sizes were obtained by co-precipitation method. The microstructure and morphology were investigated by XRPD, TEM and gas porosimetry. The luminescence properties were studied by excitation and emission spectra, quantum yield and decay times. Thermoluminescence measurements were performed to evaluate the activation energy, traps redistribution and frequency factor. Limitation in the energy transfer between dopant ions in the small particles, traps depth and surface defects were considered and investigated as responsible for the quenching of persistent luminescence. The phosphors annealed at 1100 °C show the optimal persistent luminescence and nano-particle size.

Size-Dependent Persistent Luminescence of YAGG:Cr3+ Nanophosphors

“…This is because the peak has not shifted as the initial population of trapped charges decreases. From the point of view of the activation energy, the first maximum in all samples is the same and is about 0.75 ± 0.02 eV, which is close to the value observed previously for the same matrix with different co-dopants [17,40]. In contrast, the activation energy of the second maximum noticeably decreased from about 0.9 to 0.5 eV with increasing an annealing temperature.…”

“…The signal was collected using PMT R13456 (Hamamatsu Photonics, Shizuoka, Japan Shizuoka, Japan) with a filter 721/65 Brighline HC (Semrock Inc., Rochester, NY, USA). Powder samples were prepared for measurements the same as was described in our previous work [17] For detailed analyses of the traps redistribution as an annealing temperature function, the T max -T stop (partial cleaning) experiment proposed by McKeever was performed [21]. The sample was irradiated at room temperature with the following partially heating to a temperature T stop and cooling back to room temperature (25 • C).…”

“…As can be seen from the results of structural studies carried out for the samples doped with chromium, three critical temperatures can be distinguished for the powders studied, namely 900, 1100, and 1300˚C. At 900˚C, crystal structure formation was observed for the garnet synthesis by the Pechini method [17]. The temperature of 1100˚C was chosen based on the minimum values of the lattice parameter and the particle size, which is still less than 100 nm.…”

“…Furthermore, the duration and color of PersL are determined by the luminescence center. Therefore, the use of Cr ions both as an independent dopant and as a co-dopant extends the emission time for most of the used matrices and shifts the emission range to the NIR region [9,[16][17][18].…”

Effect of co-dopant proportion on the structural, optical and magnetic properties of pristine NiO nanoparticles synthesized by Sol–gel method

“…Subsequently, which it is also growing near to the NiO lattice, 2. The presence of dopants will affect the surface energy or the energy of grain boundaries through its interacts with surface/grain boundaries, which may lead to the creation of more surfaces/grain boundaries [25]. The earlier author, Oindrila Mondal et al, have also reported the influence on various dopants with different ionic radii in CaTiO 3 .…”