LUMINESCENCE CHARACTERISTICS OF RARE-EARTH ERBIUM ION-DOPED NANOCRYSTALLINE ZINC OXIDE

2009 ◽  
Vol 18 (04) ◽  
pp. 649-656 ◽  
Author(s):  
SONG GUO-LI
Keyword(s):  
Doping Concentration ◽  
Annealing Temperature ◽  
Emission Spectra ◽  
Chemical Precipitation ◽  
Nanocrystalline Powders ◽  
Precipitation Method ◽  
Characteristic Emission ◽  
Excitation State ◽  
Pl Intensity ◽  
The Relationship

Er3+ -doped ZnO nanocrystalline powders are successfully prepared by the chemical precipitation method, using various doping concentrations of Er3+ at different annealing temperatures from 500°C to 900°C. The characteristic emission peaks of the excitation state 4S3/2 (550 nm), 2 H 11/2 (520 nm), 4 F 5/2 (455 nm) → 4 I 15/2 transition of Er3+ ions are observed in a wide visible band of the ZnO host. The relationship between the PL intensity of integration of nanocrystalline ZnO:Er3+ and the annealing temperature and doping concentration of Er3+ is given; it is found that the optimal dopant concentration and annealing temperature are 4.0 × 10-3 M and 850°C for the 4 S 3/2 → 4 I 15/2 (550 nm) and 4 F 5/2 → 4 I 15/2 (455 nm) transition of Er3+ . Based on these results, the mechanism of the emission spectra of ZnO is analyzed and its defects on the spectral properties are discussed. An energy transfer from excited states of ZnO hosts to doping Er3+ ion centers is revealed by the fact that PL intensity of the peaks of nanocrystalline ZnO:Er3+ changes with the annealing temperature and doping concentration of Er3+ , and another from the 4f–4f transition of Er3+ .

scholarly journals Crystal Chemistry and Luminescence Properties of Eu-Doped Polycrystalline Hydroxyapatite Synthesized by Chemical Precipitation at Room Temperature

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 250 ◽  
Author(s):  
Francesco Baldassarre ◽  
Angela Altomare ◽  
Nicola Corriero ◽  
Ernesto Mesto ◽  
Maria Lacalamita ◽  
...  
Keyword(s):  
Fourier Transform ◽  
High Temperature ◽  
Inductively Coupled Plasma ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Inductively Coupled

Europium-doped hydroxyapatite Ca10(PO4)6(OH)2 (3% mol) powders were synthesized by an optimized chemical precipitation method at 25 °C, followed by drying at 120 °C and calcination at 450 °C and 900 °C. The obtained nanosized crystallite samples were investigated by means of a combination of inductively coupled plasma (ICP) spectroscopy, powder X-ray diffraction (PXRD), Fourier Transform Infrared (FTIR), Raman and photoluminescence (PL) spectroscopies. The Rietveld refinement in the hexagonal P63/m space group showed europium ordered at the Ca2 site at high temperature (900 °C), and at the Ca1 site for lower temperatures (120 °C and 450 °C). FTIR and Raman spectra showed slight band shifts and minor modifications of the (PO4) bands with increasing annealing temperature. PL spectra and decay curves revealed significant luminescence emission for the phase obtained at 900 °C and highlighted the migration of Eu from the Ca1 to Ca2 site as a result of increasing calcinating temperature.

Luminescence Properties of ZnO:Eu3+ Red Emitting Phosphor Prepared by Precipitation Method

2013 ◽  
Vol 690-693 ◽  
pp. 594-597
Author(s):  
Lin Yan Jia ◽  
Zhong Bao Shao ◽  
Jun Feng Han
Keyword(s):  
Doping Concentration ◽  
Emission Spectra ◽  
Electric Dipole Transition ◽  
Dipole Transition ◽  
Luminescence Properties ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Matrix Lattice ◽  
Red Emitting Phosphor

Zinc oxide doped with Eu3+ ions red emitting phosphors were prepared by precipitation method, and its luminescence properties were investigated. The phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectra. The ZnO:Eu3+ phosphors were obtained at 600°C by calcining precipitation precursor. These phosphors can be effectively excited at 465nm. In emission spectra, the strongest peak at 616nm correlating to red emission is due to the electric dipole transition 5D07F2 of Eu3+ ions. Eu3+ions replaced Zn2+ ions and occupied the non-centrosymmetric sites in the ZnO matrix lattice. The phosphor particles with narrow distribution range are approximately 100-200nm in size. The luminescence properties of ZnO:Eu3+ phosphor with 8 mol% doping concentration of Eu3+ is optimal.

Effect of Heat Treatment on the Phase Transformation from SnS to Pure SnS2

2013 ◽  
Vol 829 ◽  
pp. 141-146
Author(s):  
Rahim Lotfi Orimi ◽  
Seyed Javad Mirdeylami
Keyword(s):  
Heat Treatment ◽  
Emission Spectra ◽  
Blue Shift ◽  
Chemical Precipitation ◽  
Treatment Temperature ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Absorption Studies ◽  
Absorbance Spectra

SnS2nanoparticles were prepared by heat treatment of SnS nanoparticles at 300 °C under N2atmosphere for 1hour. SnS nanoparticles have been synthesized by chemical precipitation method. As synthesized SnS nanoparticles, for determining the optimal temperature, were heated at various temperatures; 100, 150, 200, 250 and 300 °C N2atmosphere for 1hour. The products are characterized by X-ray diffraction (XRD) , ultraviolet visible (UV-vis) absorbance spectra and photoluminescence (PL). XRD and optical absorption studies show an increase in particle size with increasing heat treatment temperature from 100 to 200 °C . However, a large decrease in the nanoparticle size along with transforming from SnS to SnS2 is observed at 300 °C.In addition, the optical properties of al samples , including both UV-vis absorption and emission spectra showed a blue shift as the particles size decreased.

Effect of doping concentration and annealing temperature on luminescence properties of Y2O3:Eu3+ nanophosphor prepared by colloidal precipitation method

2012 ◽  
Vol 132 (8) ◽  
pp. 2023-2029 ◽  
Author(s):  
G. Siddaramana Gowd ◽  
Manoj Kumar Patra ◽  
Sandhya Songara ◽  
Anuj Shukla ◽  
Manoth Mathew ◽  
...  
Keyword(s):  
Doping Concentration ◽  
Annealing Temperature ◽  
Luminescence Properties ◽  
Precipitation Method ◽  
Effect Of Doping

Annealing Temperature Effect on the Photoluminescence Properties of Er-Doped Silicon-Rich Silicon Oxide Films

2013 ◽  
Vol 721 ◽  
pp. 16-19
Author(s):  
Chang Qing Li ◽  
Pei Jia Liu ◽  
Yong Mei Wang ◽  
K. Murakami
Keyword(s):  
Annealing Temperature ◽  
Silicon Oxide ◽  
Photoluminescence Properties ◽  
Transmission Electron ◽  
Si Nanocrystals ◽  
Large Particles ◽  
Different Temperatures ◽  
Pl Intensity ◽  
Er Doped ◽  
The Relationship

Er-dispersed silicon-rich silicon oxide (SRSO:Er) films have been fabricated by pulsed laser ablation technique. After deposition, the films were annealed in Ar ambient at different temperatures for 30 min to generate SiO2films containing Si nanocrystals (Si-nc) and Er ions. The relationship between Er photoluminescence (PL) intensity and annealing temperature was investigated by PL spectrums analysis at room temperature. Transmission Electron Microscopy (TEM) and Energy Dispersive X-ray Spectrometer (EDS) were used to observe the samples. Experimental results show that high-density Si-nc generate when the annealing temperature increases to 1000°C, however, PL intensity of Er decreases due to Er atoms segregated out in SiO2film and formed large particles.

scholarly journals Role of annealing temperature on the properties of SrO nanoparticles by precipitation method

2020 ◽  
Vol 1 (1) ◽  
pp. 18-23
Author(s):  
Suresh R ◽  
◽  
Indira Priyadharshini T ◽  
Thirumal Valavan K ◽  
Justin Paul M ◽  
...  
Keyword(s):  
Single Phase ◽  
Annealing Temperature ◽  
Surface Defects ◽  
Visible Region ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Crystalline Nature ◽  
Diffraction Peaks

Strontia nanoparticles are successfully prepared by chemical precipitation method. The SrO nanoparticles are characterized by XRD, UV-DRS and I-V analysis. X-ray diffraction peaks reveal the single-phase polycrystalline tetragonal structure with preferential orientation along (2 0 2) direction. Influence of annealing temperature strongly induce the growth of peak which indicates the increased intensity of (202) peak. The heat treatment strongly distresses the growth of triplet peaks (002), (101) and (110) whereas the same augment the growth of (202) and (310). Strontium oxide nanoparticles would allow more light for absorption in UV region due to its rough surface whereas the same would allow moderate light absorption in visible region due to its high packing density. The expansion and contraction of Sr-O bonds leads to a high crystalline nature with its purity at 322 nm. It is proposed that strain and surface defects in SrO nanocrystal take place due to different absorption edge.

scholarly journals Preparation and Study of the Effect of Annealing Temperature on the Structural, Optical, and Morphological Properties of Nanocrystalline SnO2 Doped with Cu

2021 ◽  
Vol 8 (2) ◽  
pp. 28-40
Author(s):  
Nada Abbas ◽  
Duha S. Shaker
Keyword(s):  
Spray Pyrolysis ◽  
Annealing Temperature ◽  
Spray Pyrolysis Technique ◽  
Chemical Precipitation ◽  
Morphological Properties ◽  
Precipitation Method ◽  
Pure Sno2 ◽  
Nanocrystalline Films ◽  
Force Microscopy ◽  
Atomic Force

In this study, pure SnO2 nanocrystalline films were doped with copper using the spray pyrolysis technique. SnCl2.2H2O, CuCl2.2H2O were used as precursors. The preparation was done in the form of nanoparticles by chemical precipitation method. The prepared materials were annealed at 300°C and 500°C for 1 h to improve crystallization. XRD results of the samples prepared by spray pyrolysis of a solution containing nanoparticles showed that the samples were crystallized in the rutile tetragonal phase. The average crystal size of SnO2 annealed at 300°C is 3.36 and 3.37 nm for pure and doped samples, respectively, and it is 4.1 nm and 9.75 nm for pure and doped annealed at 500°C, respectively. It is noticed that the crystal structure of SnO2 does not change with the addition of copper, and the studies of Field Emission Scanning Electron Microscopy confirmed the results where the grain size was within the range (20-50) nm, and the thickness of the films obtained from this assay was in the range (0.9-1.15) µm, with the thickness of doped films at 500°C are higher than those at 300°C. The Atomic Force Microscopy results showed that the roughness rate of the pure films annealed at 300°C and 500°C is 7.99 and 17.4 nm, respectively, while roughness for doped annealed samples were 9.09 and 7.12 nm, respectively. The optical results obtained from UV-Vis analysis showed that the optical bandgap at 300°C for pure and doped samples was (3.40 and 2.8) eV, respectively, while it was (3.75 and 2.59) eV at 500°C for pure and doped samples, respectively. The transmittance decreases with increasing annealing temperature, because the absorbance increases. The extinction coefficient increases, while refractive index decreases with increasing annealing temperature. The absorbance was 0.94 and 1.17 for pure and doped samples at 300°C, and was 1.16 and 1.46 at 500°C.

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