A Novel Route to Octahedral In2O3Particles Exhibiting Near Band Emission

2005 ◽  
Vol 34 (1) ◽  
pp. 118-119 ◽  
Author(s):  
Wu Zhang ◽  
Zhen Huang ◽  
Ting Li ◽  
Qun Tang ◽  
Dekun Ma ◽  
...  
Keyword(s):  
Band Emission ◽  
Near Band Emission

Photoluminescence from ZnO Thin Film Deposited on R-Plane Sapphire Substrate by RF Magnetron Sputtering

2008 ◽  
Vol 388 ◽  
pp. 19-22 ◽  
Author(s):  
Shigeru Tanaka ◽  
Yukari Ishikawa ◽  
Toshiyuki Suzuki ◽  
Noriyoshi Shibata
Keyword(s):  
Thin Film ◽  
Magnetron Sputtering ◽  
Sapphire Substrate ◽  
Rf Magnetron Sputtering ◽  
Zno Thin Film ◽  
Excitation Light ◽  
Sapphire Substrates ◽  
Band Emission ◽  
Near Band Emission ◽  
Zno Crystal

Photoluminescence from epitaxial ZnO thin films deposited on R-plane sapphire substrates by RF magnetron sputtering was investigated. The intensity of the near band emission (NBE) of the ZnO thin film on R-plane sapphire was stronger than that of the film formed on C-plane sapphire at a low temperature. Some experimental results suggest that NBE depends on the polarization of the excitation light, which are considered to be related to the ZnO crystal orientation on the sapphire substrate.

Raman Scattering and Photoluminescence Studies of Zn1-xMnxO Nanowires via Vapor Phase Growth

2005 ◽  
Vol 475-479 ◽  
pp. 3525-3530 ◽  
Author(s):  
Y.Q. Chang ◽  
Yi Zhi Chen ◽  
D.P. Yu ◽  
Z.L. Fang ◽  
G.H. Li ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Raman Spectra ◽  
Vapor Phase ◽  
Phonon Frequency ◽  
Quantum Confinement Effect ◽  
Phase Growth ◽  
Vapor Phase Growth ◽  
Band Emission ◽  
Near Band Emission ◽  
Photoluminescence Studies

In this paper, we investigated the Raman scattering and photoluminescence of Zn1-xMnxO nanowires synthesized by the vapor phase growth. The changes of E2(High) and A1(LO) phonon frequency in Raman spectra indicate that the tensile stress increases while the free carrier concentration decreases with the increase of manganese. The Raman spectra exited by the different lasers exhibit the quantum confinement effect of Zn1-xMnxO nanowires. The photoluminescence spectra reveal that the near band emission is affected by the content of manganese obviously. The values of IUV/G decrease distinctly with the manganese increase also demonstrate that more stress introduced with the more substitution of Mn for Zn.

scholarly journals Structural and Enhanced Optical Properties of Stabilized γ‒Bi2O3 Nanoparticles: Effect of Oxygen Ion Vacancies

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1023 ◽  
Author(s):  
Ashish Chhaganlal Gandhi ◽  
Chia-Liang Cheng ◽  
Sheng Yun Wu
Keyword(s):  
Room Temperature ◽  
Excess Oxygen ◽  
Ambient Atmosphere ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Band Emission ◽  
Oxygen Ion ◽  
Integrated Intensity ◽  
Effect Of Oxygen

We report the synthesis of room temperature (RT) stabilized γ–Bi2O3 nanoparticles (NPs) at the expense of metallic Bi NPs through annealing in an ambient atmosphere. RT stability of the metastable γ–Bi2O3 NPs is confirmed using synchrotron radiation powder X-ray diffraction and Raman spectroscopy. γ–Bi2O3 NPs exhibited a strong red-band emission peaking at ~701 nm, covering 81% integrated intensity of photoluminescence spectra. Our findings suggest that the RT stabilization and enhanced red-band emission of γ‒Bi2O3 is mediated by excess oxygen ion vacancies generated at the octahedral O(2) sites during the annealing process.

4U 1608–52 as a quasi-persistent X-ray source

2020 ◽  
Vol 72 (6) ◽  
Author(s):  
Vojtěch Šimon
Keyword(s):  
Accretion Disk ◽  
Time Segment ◽  
X Ray ◽  
Band Emission ◽  
Heating And Cooling ◽  
Soft State ◽  
Cyclic Variations ◽  
Low Mass ◽  
X Ray Binaries ◽  
Disk Region

Abstract 4U 1608–52 is a soft X-ray transient. The analysis presented here of a particular part of its X-ray activity uses observations of RXTE/ASM and Swift/BAT. We show a time segment (MJD 54262–MJD 55090) (828 d) in which 4U 1608–52 behaved as a quasi-persistent X-ray source with a series of bumps, with a complicated relation between the evolution of fluxes in the soft (1.5–12 keV) and the hard (15–50 keV) X-ray regions. We ascribe these bumps to a series of propagations of heating and cooling fronts over the inner disk region without any transitions to the true quiescence. 4U 1608–52 oscillated around the boundary between the dominance of the Comptonized component and the dominance of the multicolor accretion disk in its luminosity. Only some of the bumps in this series were accompanied by a transition from the hard to the soft state; if it occurred, it displayed a strong hysteresis effect. The hard-band emission with the dominant Comptonized component was present for most of this active state and showed a cycle of about 40 d. We argue that the cyclic variations of flux come from the inner disk region, not, e.g., from a jet. We also discuss the observed behavior of 4U 1608–52 in the context of other quasi-persistent low-mass X-ray binaries.

scholarly journals The challenging SED of AP Librae

2011 ◽  
Vol 7 (S284) ◽  
pp. 411-413 ◽  
Author(s):  
David Sanchez ◽  
Berrie Giebels ◽  
Pascal Fortin ◽  
Keyword(s):  
Spectral Energy Distribution ◽  
Broad Band ◽  
Low Frequency ◽  
Theoretical Models ◽  
Intermediate Frequency ◽  
High Energy ◽  
Spectral Energy ◽  
Broad Band Emission ◽  
Band Emission ◽  
Bl Lac

AbstractMatching the broad-band emission of active galaxies with the predictions of theoretical models can be used to derive constraints on the properties of the emitting region and to probe the physical processes involved. AP Librae is the third low frequency peaked BL Lac (LBL) detected at very high energy (VHE, E>100GeV) by an Atmospheric Cherenkov Telescope; most VHE BL Lacs (34 out of 39) belong to the high-frequency and intermediate-frequency BL Lac classes (HBL and IBL). LBL objects tend to have a higher luminosity with lower peak frequencies than HBLs or IBLs. The characterization of their time-averaged spectral energy distribution is challenging for emission models such as synchrotron self-Compton (SSC) models.

Size-Dependence of Photoluminescence Property of ZnO Nanoparticles

2014 ◽  
Vol 887-888 ◽  
pp. 143-146 ◽  
Author(s):  
Xiao Fang Wang ◽  
Yun Liang Fang ◽  
Tian Le Li ◽  
Fu Juan Wang
Keyword(s):  
Grain Size ◽  
Lower Energy ◽  
Size Dependence ◽  
Surface States ◽  
Photoluminescence Property ◽  
Precipitation Method ◽  
Pl Spectra ◽  
Broadband Emission ◽  
Band Emission ◽  
20 Nm

Nanometer-sized ZnO crystals with the diameter from 20 nm to 110 nm were prepared by homogenous precipitation method (HPM). The photoluminescence (PL) spectra of as-prepared nanoparticles under excitation at the wavelength of 320 nm were detected. The PL spectra were fitted with Gaussian curves, in which a good fitting consisting of six Gaussian peaks was obtained. We observed that the multi-peak centers do not change much, while the relative amplitude of Gaussian combination to the band-to-band emission decreases rapidly with the increased grain size. It shows that the broadband emission at the lower energy is associated with the surface states.

Microscintillator of Ce Doped β-NaLuF4 in Uniform Hexagonal Prism Morphology by a Facile Hydrothermal Method

2014 ◽  
Vol 541-542 ◽  
pp. 220-224
Author(s):  
Li Sha Liu ◽  
Hao Hong Chen ◽  
Bi Qiu Liu ◽  
Bin Tang ◽  
Zhi Jia Sun ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Hexagonal Phase ◽  
Broad Band ◽  
High Energy ◽  
Hexagonal Prism ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Strong Broad Band ◽  
Broad Band Emission ◽  
Band Emission

To explore micro-or nanoscintillator with a controllable architecture, a novel facile hydrothermal method easy for commercial run was used to synthesize pure and Ce doped β-NaLuF4 microcrystals at 453K. The morphology of uniform hexagonal prism with 3.3μm in diameter and 1.4 μm in thickness, respectively, is presented by the results of scanning electron microscopy (SEM). Powder X-ray diffraction (PXRD) patterns show the products are both pure hexagonal phase. Different from the undoped product without any irradiation, the Ce doped product has given strong broad band emission attributed to 5d4f transition of Ce3+, which can be potentially used as scintillator for biomedical imaging and detectors for high energy such as X-ray and γray. This synthetical strategy extends the understanding about nanomaterial chemistry and can be also useful for other systems such as fluorides, oxides and sulfides.

Preparation and Luminescence Property of LaMgAl11O19

2012 ◽  
Vol 519 ◽  
pp. 224-227 ◽  
Author(s):  
Xin Min ◽  
Ming Hao Fang ◽  
Yan Gai Liu ◽  
Zhao Hui Huang
Keyword(s):  
Solid State ◽  
Luminescence Property ◽  
Broad Band ◽  
Emission Spectra ◽  
Synthesis Temperature ◽  
Solid State Lasers ◽  
Broad Band Emission ◽  
Band Emission ◽  
Air Atmosphere ◽  
Fluorescent Lamps

Lanthanum magnesium hexaaluminate (LaMgAl11O19, LMA) has attracted much interest as its widely used in solid state lasers, TV phosphors and fluorescent lamps. In this paper, LaMgAl11O19 ceramic was pressureless sintered at 1650 °C for 10 h in air atmosphere using LaMgAl11O19 powders prepared by solid-state reaction at 1500 °C for 4 h. The result indicated that the synthesis temperature of LaMgAl11O19 powders was about 1500 °C. The LMA ceramic sample was dense and had a microstructure of platelet-like gains. The excitation spectrum shows two wide bands with the peaks at about 254 nm and 265 nm by monitoring the strongest 362 nm emission, and the emission spectra is consisted of a broad band emission with their peaks near 362 nm with a half-width about 5 nm exciting with 265 nm wavelength.

Correlating Multicrystalline Silicon Defect Types Using Photoluminescence, Defect-band Emission, and Lock-in Thermography Imaging Techniques

2014 ◽  
Vol 4 (1) ◽  
pp. 348-354 ◽  
Author(s):  
Steve Johnston ◽  
Harvey Guthrey ◽  
Fei Yan ◽  
Katherine Zaunbrecher ◽  
Mowafak Al-Jassim ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Multicrystalline Silicon ◽  
Defect Band ◽  
Band Emission ◽  
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