EVOLUTION OF LUMINESCENCE SPECTRA OF Ce3+-ION IN THE SOLID SOLUTIONS Ca1-xSrxS

2006 ◽  
Vol 20 (22) ◽  
pp. 1405-1416 ◽  
Author(s):  
O. KRACHNI ◽  
L. GUERBOUS ◽  
L. LOUAIL
Keyword(s):  
Band Gap ◽  
Lattice Constant ◽  
Solid Solutions ◽  
Local Structure ◽  
Emission Spectra ◽  
Host Lattice ◽  
Luminescence Properties ◽  
Luminescence Spectra ◽  
Additional Band

Luminescence spectra of Ce 3+-ion in Ca 1-x Sr x S solid solutions have been investigated. It has been shown that the evolution of Ce 3+ excitation and emission spectra through the concentration range may be interpreted in correlation with the variations, with the host lattice composition, of the lattice constant, the local structure in the activator neighborhood and the band gap. Under activator excitation, in addition to the two conventional bands, an additional band peaking at about 650 nm was observed (mainly in SrS ) and was related to the contamination of the samples as a consequence of extended storage. Except for this band, the luminescence properties did not change relatively to those obtained previously on the same samples. The most drastic modification affected SrS:Ce 3+, despite the fact that all the samples have been stored in the same conditions.

Mn4+ Activated Deep Red Emitting Perovskite Type Phosphors for Horticulture Lighting

2021 ◽  
Vol 1167 ◽  
pp. 57-66
Author(s):  
Muhammad Khurram ◽  
Florian Baur ◽  
Thomas Juestel
Keyword(s):  
Emission Spectra ◽  
Host Lattice ◽  
Luminescence Spectra ◽  
Quenching Temperature ◽  
Light Emitting ◽  
Thermally Activated ◽  
Host Materials ◽  
Colour Rendering ◽  
Perovskite Type ◽  
Pl Quenching

Red emitting Mn4+ doped oxides are a promising class of materials to improve the colour rendering and luminous efficacy of phosphor-converted light-emitting diodes (pcLEDs). For pcLEDs, the optical properties are crucial w.r.t commercial acceptance. In this work, luminescence spectra and decay curves of Sr2YNbO6, Sr2YTaO6 and Sr2LaNbO6 have been recorded, other Mn4+ doped phosphors show that quenching occurs through thermally activated crossover between the 4T2 excited state and 4A2 ground state. The quenching temperature can be optimized by designing the host lattice in which Mn4+ has a high 4T2 state energy. The main target is to study the influence of the above-mentioned host materials on the emission spectra, PL quenching, and quantum yield of the deep red Mn4+ ion. The present study provides detailed insights into temperature and concentration quenching of Mn4+ emission and can be used to realize superior narrow-band red Mn4+ phosphors for horticultural lighting.

Comparable Structural and Luminescent Characterization of the La1-xEuxVO4 Solid Solutions Synthesized by Solid State and Co-Precipitation Methods

2013 ◽  
Vol 200 ◽  
pp. 186-192 ◽  
Author(s):  
Oksana Chukova ◽  
Sergiy G. Nedilko ◽  
Sergiy A. Nedilko ◽  
Vasyl Sherbatsky ◽  
Tetiana Voitenko
Keyword(s):  
Solid State ◽  
Solid Solutions ◽  
Spectral Lines ◽  
Luminescence Properties ◽  
Luminescence Spectra ◽  
Excitation Spectra ◽  
Electron Transitions ◽  
Charge Transfer Transitions ◽  
The Matrix ◽  
Co Precipitation

Luminescence properties of the two series of the La1-xEuxVO4 (x ranges from to 0.3) solid solutions synthesized by the solid state and co-precipitation methods were investigated.. Luminescence spectra of the investigated samples consist of narrow spectral lines caused by inner f - f electron transitions in the impurity Eu3+ ions. Excitation spectra consist of three main bands those correspond to different types of transitions in the investigated matrices. There are O - Eu3+ charge transfer transitions, band-to-band transitions in the matrix of the vanadate compounds and electron transitions in the VO43- vanadate anion. Dependences of the structure and luminescence properties on rate compositions and method of synthesis were studied. Origins of the observed differences between luminescence characteristics of the samples obtained by two different methods are discussed.

Luminescence Studies on Lithium-Strontium Borophosphate Glasses Doped with Cr, Ni and Zn Ions

2012 ◽  
Vol 626 ◽  
pp. 16-20 ◽  
Author(s):  
Poh Sum Wong ◽  
Wan Ming Hua ◽  
Rosli Hussin ◽  
Zuhairi Ibrahim
Keyword(s):  
Transition Metal ◽  
Metal Ions ◽  
Metal Ion ◽  
Emission Spectra ◽  
Transition Metal Ions ◽  
Photoluminescence Spectroscopy ◽  
Luminescence Properties ◽  
Luminescence Spectra ◽  
Doped Glass ◽  
Zn Ions

Luminescence material is a solid which converts certain types of energy into electromagnetic radiation over and above thermal radiation. Due to the limited studies on luminescence properties of the transition metal ion doped glass, this present study aiming to understand further the effect of doping different transition metal ions to the luminescence properties. This paper report on the luminescence properties of 20Li2O-20SrO-30B2O3-30P2O5 glasses doped from the photoluminescence spectroscopy. The luminescence spectra of 20Li2O-20SrO-30B2O3-30P2O5-x with x = 1 mol % of different transition metal ions (Cr, Ni, and Zn) which had been prepared by melt quenching technique. The luminescence properties were analyzed using photoluminescence spectroscopy. Based on the emission spectra obtained from 20Li2O-20SrO-30B2O3-30P2O5-Cr, it consists of two emission bands at around 348 nm and 369 nm. While for the luminescence spectra of 20Li2O-20SrO-30B2O3-30P2O5-Ni, it exhibits only one emission band which is at around 363 nm. Lastly, for the luminescence spectra of 20Li2O-20SrO-30B2O3-30P2O5-Zn, it exhibits two emission bands at around 379 nm and 434 nm.

Synthesis and Luminescence Properties of YVO4:Eu 3+ Nanocrystals by a Sol-Gel Method

2013 ◽  
Vol 634-638 ◽  
pp. 2268-2271 ◽  
Author(s):  
Yan Hong Li ◽  
Guo Feng Zang ◽  
Jing Ma
Keyword(s):  
Charge Transfer Band ◽  
Sol Gel ◽  
Emission Spectra ◽  
Heat Treating ◽  
Luminescence Properties ◽  
Luminescence Spectra ◽  
Complexing Agent ◽  
Gel Method ◽  
Sol Gel Method ◽  
Crystallite Sizes

YVO4:Eu3+ nanocrystals were synthesized using a sol-gel method which citric acid was used as complexing agent and ethylene glycol was used as coupler. In order to study the influence of heat treating temperature and time on structure and luminescence properties of YVO4:Eu3 nanocrystals, the dry gels were heated at 400 oC, 500 oC and 600 oC for 1 h, 600 o C for 3 h, respectively. X-ray diffraction, SEM and luminescence spectra were used to characterize the structure and luminescence properties. The results of XRD indicate that YVO4:Eu3+ nanocrystals with tetragonal zircon were obtained. The average crystallite sizes of the samples increase with the increasing heat treating temperatures. The results of excitation and emission spectra show that the broad excitation band is assigned to charge transfer band of Eu-O and V-O, the emissions peaks are from 5D0-7FJ transitions. The emission intensities increase with increasing heat treating temperature and time. The local environments of Eu3+ ions in the samples prepared at different conditions are discussed.

Local structure of Ba(Ti,Zr)O3perovskite-like solid solutions and its relation to the band-gap behavior

2011 ◽  
Vol 83 (9) ◽  
Author(s):  
Igor Levin ◽  
Eric Cockayne ◽  
Victor Krayzman ◽  
Joseph C. Woicik ◽  
Soonil Lee ◽  
...  
Keyword(s):  
Band Gap ◽  
Solid Solutions ◽  
Local Structure

scholarly journals Influence of Calcination Temperature on Crystal Growth and Optical Characteristics of Eu3+ Doped ZnO/Zn2SiO4 Composites Fabricated via Simple Thermal Treatment Method

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 115
Author(s):  
Suhail Huzaifa Jaafar ◽  
Mohd Hafiz Mohd Zaid ◽  
Khamirul Amin Matori ◽  
Sidek Hj. Ab Aziz ◽  
Halimah Mohamed Kamari ◽  
...  
Keyword(s):  
Thermal Treatment ◽  
Band Gap ◽  
Calcination Temperature ◽  
Emission Intensity ◽  
Emission Spectra ◽  
Treatment Method ◽  
Absorption Bands ◽  
Vis Spectroscopy ◽  
Doped Zno ◽  
Zno Crystal

This research paper proposes the usage of a simple thermal treatment method to synthesis the pure and Eu3+ doped ZnO/Zn2SiO4 based composites which undergo calcination process at different temperatures. The effect of calcination temperatures on the structural, morphological, and optical properties of ZnO/Zn2SiO4 based composites have been studied. The XRD analysis shows the existence of two major phases which are ZnO and Zn2SiO4 crystals and supported by the finding in the FT-IR. The FESEM micrograph further confirms the existence of both ZnO and Zn2SiO4 crystal phases, with progress in the calcination temperature around 700–800 °C which affects the existence of the necking-like shape particle. Absorption humps discovered through UV-Vis spectroscopy revealed that at the higher calcination temperature effects for higher absorption intensity while absorption bands can be seen at below 400 nm with dropping of absorption bands at 370–375 nm. Two types of band gap can be seen from the energy band gap analysis which occurs from ZnO crystal and Zn2SiO4 crystal progress. It is also discovered that for Eu3+ doped ZnO/Zn2SiO4 composites, the Zn2SiO4 crystal (5.11–4.71 eV) has a higher band gap compared to the ZnO crystal (3.271–4.07 eV). While, for the photoluminescence study, excited at 400 nm, the emission spectra of Eu3+ doped ZnO/Zn2SiO4 revealed higher emission intensity compared to pure ZnO/Zn2SiO4 with higher calcination temperature exhibit higher emission intensity at 615 nm with 700 °C being the optimum temperature. The emission spectra also show that the calcination temperature contributed to enhancing the emission intensity.

Optical Properties and Zinc Nitride Thin Films Prepared Using Magnetron Reactive Sputtering

2014 ◽  
Vol 940 ◽  
pp. 11-15
Author(s):  
Jun Qin Feng ◽  
Jun Fang Chen
Keyword(s):  
Thin Films ◽  
Band Gap ◽  
Near Infrared ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Sem Images ◽  
Fluorescence Emission Spectra ◽  
Glass Substrates ◽  
Zinc Nitride ◽  
Direct Band

Zinc nitride films were deposited by ion sources-assisted magnetron sputtering with the use of Zn target (99.99% purity) on 7059 glass substrates. The films were characterized by XRD, SEM and EDS, the results of which show that the polycrystalline zinc nitride thin film can be grown on the glass substrates, the EDS spectrum confirmed the chemical composition of the films and the SEM images revealed that the zinc nitride thin films have a dense structure. Ultraviolet-visible-near infrared spectrophotometer was used to study the transmittance behaviors of zinc nitride thin films, which calculated the optical band gap by Davis Mott model. The results of the fluorescence emission spectra show the zinc nitride would be a direct band gap semiconductor material.

NIR and Upconversion Luminescence Properties of Nd3+ Doped in Gd2O3-CaO-SiO2-B2O3 Glass System

2014 ◽  
Vol 548-549 ◽  
pp. 124-128 ◽  
Author(s):  
S. Insiripong ◽  
S. Kaewjeang ◽  
U. Maghanemi ◽  
H.J. Kim ◽  
N. Chanthima ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Upconversion Luminescence ◽  
Emission Spectra ◽  
Concentration Quenching ◽  
Luminescence Spectra ◽  
Optical Absorption Spectra ◽  
Glass Matrices ◽  
Nir Luminescence

In this work, properties of Nd3+ in Gd2O3-CaO-SiO2-B2O3 glass systems with composition 25Gd2O3-10CaO-10SiO2-(55-x)B2O3-xNd2O3 where x = 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol% were investigated. The optical absorption spectra show peaks at 4F3/2 (877 nm) , 4F5/2+2H9/2 (802 nm), 4F7/2+4S3/2 (743 nm), 4F9/2 (682 nm), 2H11/2 (627 nm), 2G7/2 +4G5/2 (582 nm), 4G7/2 +2K13/2 (527 nm), 4G11/2 (481 nm), 2P1/2 (427 nm) and 2L15/2 + 4D1/2 + 1I11/2+ 4D5/2+ 4D3/2 (355 nm) reflecting the Nd3+ ions in glass matrices. The densities were increased with increasing of Nd2O3 concentration. This indicates the increase of the molecular weight by the replacement of B2O3 with a heavier Nd2O3 oxide in the glass. The upconversion luminescence spectra show bands at 393 nm for all Nd2O3 concentration and the strongest intensity from 2.5 % mol of Nd2O3 was obtained. For NIR luminescence, the intensity of Nd3+ emission spectra increases with increasing concentrations of Nd3+ up to 1.5 mol% and beyond 1.5 mol% the concentration quenching is observed.

Band-Gap Energy Dependence of Emission Spectra in Rare Earth-Doped Zn(1-x)CdxS Thin Film Electroluminescent Devices

1992 ◽  
Vol 31 (Part 1, No. 2A) ◽  
pp. 295-300 ◽  
Author(s):  
Noboru Miura ◽  
Takashi Sasaki ◽  
Hironaga Matsumoto ◽  
Ryotaro Nakano
Keyword(s):  
Thin Film ◽  
Rare Earth ◽  
Band Gap ◽  
Energy Dependence ◽  
Emission Spectra ◽  
Band Gap Energy ◽  
Electroluminescent Devices ◽  
Gap Energy ◽  
Rare Earth Doped

ELECTRON STRUCTURE INVESTIGATIONS OF InGaP/GaAs(100) HETEROSTRUCTURES WITH InP QUANTUM DOTS

2007 ◽  
Vol 06 (03n04) ◽  
pp. 215-219
Author(s):  
E. P. DOMASHEVSKAYA ◽  
V. A. TEREKHOV ◽  
V. M. KASHKAROV ◽  
S. YU. TURISHCHEV ◽  
S. L. MOLODTSOV ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Emission Spectra ◽  
Luminescence Spectra ◽  
Partial Density ◽  
Edge Structure ◽  
X Ray ◽  
Metal Organic ◽  
Structure Investigations ◽  
First Time ◽  
Inp Quantum Dots

Ultrasoft X-ray emission spectra (USXES) and X-ray absorption near-edge structure (XANES) spectra with the use of synchrotron radiation in the range of P L2,3-edges were obtained for the first time for nanostructures with InP quantum dots grown on GaAs 〈100〉 substrates by vapor-phase epitaxy from metal–organic compounds. These spectra represent local partial density of states in the valence and conduction bands. The additional XANES peak is detected; its intensity depends on the number of monolayers forming quantum dots. Assumptions are made on the band-to-band origin of luminescence spectra in the studied nanostructures.

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