Search results for "Persistent luminescence"
showing 10 items of 14 documents
Recent progress in understanding the persistent luminescence in SrAl 2 O 4 :Eu,Dy
2019
Ever since the discovery of SrAl2O4:Eu,Dy persistent afterglow material, that can intensively glow up to 20 h, the mechanism of long-lasting luminescence has been a popular area of research. The re...
Effect of annealing temperature on persistent luminescence of Y3Al2Ga3O12:Cr3+ co-doped with Ce3+ and Pr3+
2021
Abstract Y3(Al,Ga)5O12 (YAGG) materials doped with Ce3+, Cr3+ and Pr3+ were synthesized by using a modified Pechini method and subsequently annealed in air at selected temperatures between 900 and 1500 °C. According to X-ray powder diffraction (XRPD) and transmission electron microscopy (TEM) analyses, the particles and size distributions become large and broad, respectively, due to sintering and agglomeration at high annealing temperatures. Based on infrared (FTIR) spectra and calculation of multi-phonon de-excitation probabilities, the high energy O–H vibrations are not causing significant multi-phonon de-excitation of the emitting 5d level of Ce3+ if the annealing temperature is above 90…
Hackmanite—The Natural Glow-in-the-Dark Material
2020
“Glow-in-the-dark” materials are known to practically everyone who has ever traveled by airplane or cruise ship, since they are commonly used for self-lit emergency exit signs. The green afterglow, persistent luminescence (PeL), is obtained from divalent europium doped to a synthetic strontium aluminate, but there are also some natural minerals capable of afterglow. One such mineral is hackmanite, the afterglow of which has never been thoroughly investigated, even if its synthetic versions can compete with some of the best commercially available synthetic PeL materials. Here we combine experimental and computational data to show that the white PeL of natural hackmanite is generated and cont…
The boron effect on low temperature luminescence of SrAl2O4:Eu, Dy
2020
V.V. acknowledges the financial support of ERDF PostDoc project No. 1.1.1.2/VIAA/3/19/440 (University of Latvia Institute of Solid State Physics, Latvia) and K.S., I.B., A.Z., D.M. and K.L. acknowledge the financial support of ERDF, European-Union Project No. 1.1.1.1/16/A/182 (University of Latvia Institute of Solid State Physics, Latvia).
Low temperature afterglow from SrAl 2 O 4 : Eu, Dy, B containing glass
2020
V.V. acknowledges the financial support of ERDF PostDoc project No. 1.1.1.2/VIAA/3/19/440 (University of Latvia Institute of Solid State Physics, Latvia) and LP the Academy of Finland (Flagship Programme, Photonics Research and Innovation PREIN 320165 and Academy Project -326418) for the financial support. Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01- 2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART 2 .
The search for defects in undoped SrAl2O4 material
2019
This research project was supported financially by ERDF Project No: Nr.1.1.1.1/16/A/182 .
Effect of annealing treatment on the persistent luminescence of Y3Al2Ga3O12:Ce3+,Cr3+,Pr3+ ceramics
2020
Abstract The Y3Al2Ga3O12:Ce3+,Cr3+,Pr3+ (YAGG) persistent luminescent ceramics were sintered in static air (without airflow) and followed by hot isostatic pressing (HIP) treatment. The low aggregated and relatively narrow particle-size distributed starting powders, with the particle size of about 50 nm, were synthesized by using Pechini method and then annealed at 900 °C for 16 h in static air. Compared to nano-phosphors, the ceramics exhibited more intense and longer persistent luminescence (PersL). The photoluminescence and PersL spectra were found to have a similar shape, indicating that the emitting centers for photoluminescence and PersL processes were same. The intense Ce3+ and Cr3+ b…
Effect of Ce3+ concentration on persistent luminescence of YAGG:Ce3+,Cr3+,Nd3+ nanophosphors obtained by the co-precipitation method
2020
Abstract Synthesis of Y3Al2Ga3O12 garnet (YAGG) nanophosphors co-doped with Ce3+, Cr3+, and Nd3+ ions by co-precipitation is reported. The effect of Ce3+ concentration on the structure of garnet and on optical properties including persistent luminescence was investigated. The X-ray diffraction measurements showed that single garnet phase was obtained. The contraction of the crystallites size was observed with increasing the cerium concentration. The combined emission of three used co-dopants together allows to extend persistent luminescence spectral range. The photoluminescence, excitation and persistent luminescence spectra were collected and the optimal Ce3+ concentration for the highest …
UV and X-ray excited red persistent luminescence in Mn2+ doped MgGeO3 material synthesized in air and reducing atmosphere
2021
Abstract Materials with long persistent luminescence (PersL) have caused widespread interest among scientists and industry for decades. Currently, there is widely available information on the long persistent luminescence materials with emission in the blue and green spectral range, while the number of publications on the afterglow in the red and near-infrared spectral range is considerably lower. In the course of this work MgGeO3 material doped with 0.1 mol% Mn2+ was produced using solid-state reaction synthesis in ambient and reducing atmospheres. The material exhibits a broad luminescence band with a peak around 680 nm, excited by either X-rays or UV. After cessation of irradiation, the a…
Enhancement of persistent luminescence in Ca2SnO4: Sm3+
2021
Abstract Reddish-orange persistent luminescent Ca2SnO4: 0.1% Sm3+ co-doped with 0–10% Gd3+ was prepared using solid state synthesis. The phase formation and morphology was analyzed using X-ray diffraction and scanning electron microscopy. Incorporation of Sm3+ and Gd3+ in Ca2SnO4 lattice was investigated using site-selective spectroscopy and electron paramagnetic resonance. In all samples reddish-orange persistent luminescence and photochromic effect was observed after excitation with UV as well as X-rays. The thermostimulated luminescence curves indicated that the introduction of Gd3+ increases the number of shallow traps of charges which enhance the intensity of persistent luminescence. I…