Up-conversion green emission of Yb 3+ /Er 3+ ions doped YVO 4 nanocrystals obtained via modified Pechini's method

2017 ◽  
Vol 74 ◽  
pp. 128-134 ◽  
Author(s):  
Agata Szczeszak ◽  
Marcin Runowski ◽  
Rafal J. Wiglusz ◽  
Tomasz Grzyb ◽  
Stefan Lis
Keyword(s):  
Green Emission ◽  
Pechini’S Method

Growth Kinetics of Quantum Size ZnO Particles

1998 ◽  
Vol 536 ◽  
Author(s):  
E. M. Wong ◽  
J. E. Bonevich ◽  
P. C. Searson
Keyword(s):  
Growth Kinetics ◽  
Ostwald Ripening ◽  
Chemical Potential ◽  
Colloidal Suspensions ◽  
Green Emission ◽  
Blue Shift ◽  
Constant Current ◽  
Mass Model ◽  
Zno Particles ◽  
Kinetics Of

AbstractColloidal chemistry techniques were used to synthesize ZnO particles in the nanometer size regime. The particle aging kinetics were determined by monitoring the optical band edge absorption and using the effective mass model to approximate the particle size as a function of time. We show that the growth kinetics of the ZnO particles follow the Lifshitz, Slyozov, Wagner theory for Ostwald ripening. In this model, the higher curvature and hence chemical potential of smaller particles provides a driving force for dissolution. The larger particles continue to grow by diffusion limited transport of species dissolved in solution. Thin films were fabricated by constant current electrophoretic deposition (EPD) of the ZnO quantum particles from these colloidal suspensions. All the films exhibited a blue shift relative to the characteristic green emission associated with bulk ZnO. The optical characteristics of the particles in the colloidal suspensions were found to translate to the films.

scholarly journals Blue-green emission from epitaxial yet cation-disordered ZnGeN2−xOx

2019 ◽  
Vol 3 (5) ◽  
Author(s):  
Celeste L. Melamed ◽  
M. Brooks Tellekamp ◽  
John S. Mangum ◽  
John D. Perkins ◽  
Patricia Dippo ◽  
...  
Keyword(s):  
Green Emission

scholarly journals Polymer Thermal Treatment Production of Cerium Doped Willemite Nanoparticles: An Analysis of Structure, Energy Band Gap and Luminescence Properties

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1118
Author(s):  
Ibrahim Mustapha Alibe ◽  
Khamirul Amin Matori ◽  
Mohd Hafiz Mohd Zaid ◽  
Salisu Nasir ◽  
Ali Mustapha Alibe ◽  
...  
Keyword(s):  
Solid State ◽  
Thermal Treatment ◽  
Band Gap ◽  
Optical Band Gap ◽  
Dopant Concentration ◽  
Blue Emission ◽  
Green Emission ◽  
Band Gap Energy ◽  
Solid State Lighting ◽  
Gap Energy

The contemporary market needs for enhanced solid–state lighting devices has led to an increased demand for the production of willemite based phosphors using low-cost techniques. In this study, Ce3+ doped willemite nanoparticles were fabricated using polymer thermal treatment method. The special effects of the calcination temperatures and the dopant concentration on the structural and optical properties of the material were thoroughly studied. The XRD analysis of the samples treated at 900 °C revealed the development and or materialization of the willemite phase. The increase in the dopant concentration causes an expansion of the lattice owing to the replacement of larger Ce3+ ions for smaller Zn2+ ions. Based on the FESEM and TEM micrographs, the nanoparticles size increases with the increase in the cerium ions. The mean particles sizes were estimated to be 23.61 nm at 1 mol% to 34.02 nm at 5 mol% of the cerium dopant. The optical band gap energy of the doped samples formed at 900 °C decreased precisely by 0.21 eV (i.e., 5.21 to 5.00 eV). The PL analysis of the doped samples exhibits a strong emission at 400 nm which is ascribed to the transition of an electron from localized Ce2f state to the valence band of O2p. The energy level of the Ce3+ ions affects the willemite crystal lattice, thus causing a decrease in the intensity of the green emission at 530 nm and the blue emission at 485 nm. The wide optical band gap energy of the willemite produced is expected to pave the way for exciting innovations in solid–state lighting applications.

scholarly journals Research of Fluorescent Properties of a New Type of Phosphor with Mn2+-Doped Ca2SiO4

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2788
Author(s):  
Xiaozhou Fan ◽  
Wenqi Zhang ◽  
Fangcheng Lü ◽  
Yueyi Sui ◽  
Jiaxue Wang ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Green Emission ◽  
Response Speed ◽  
Sintered Sample ◽  
Solid State Reaction Method ◽  
Average Lifetime ◽  
Diffraction Spectrum ◽  
Fluorescent Properties ◽  
Fluorescent Material ◽  
New Type

Fluorescent optical fiber temperature sensors have attracted extensive attention due to their strong anti-electromagnetic interference ability, good high-voltage insulation performance, and fast response speed. The fluorescent material of the sensor probe directly determines the temperature measurement effect. In this paper, a new type of fluorescent material with a Mn2+-doped Ca2SiO4 phosphor (CSO:Mn2+) is synthesized via the solid-state reaction method at 1450 °C. The X-ray diffraction spectrum shows that the sintered sample has a pure phase structure, although the diffraction peaks show a slight shift when dopants are added. The temperature dependence of the fluorescence intensity and lifetime in the range from 290 to 450 K is explored with the help of a fluorescence spectrometer. Green emission bands peaking at 475 and 550 nm from Mn2+ are observed in the fluorescence spectra, and the intensity of emitted light decreases as the temperature rises. The average lifetime of CSO:Mn2+ is 17 ms, which is much higher than the commonly used fluorescent materials on the market. The fluorescence lifetime decreases with increasing temperature and shows a good linear relationship within a certain temperature range. The research results are of great significance to the development of a new generation of fluorescence sensors.

Crystal structure, luminescence, and thermal stability of CsAlSi2O6:Tb3+ phosphors with highly efficient green emission

2021 ◽  
pp. 111441
Author(s):  
Seiya Shimono ◽  
Taichi Izaki ◽  
Nagisa Tanaka ◽  
Yasushi Nanai ◽  
Takaaki Morimoto ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Green Emission ◽  
Highly Efficient ◽  
Thermal Stability Of

scholarly journals Development of Er3+, Yb3+ Co-Doped Y2O3 NPs According to Yb3+ Concentration by LP–PLA Method: Potential Further Biosensor

Biosensors ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 150
Author(s):  
Cheol-Woo Park ◽  
Dong-Jun Park
Keyword(s):  
Pulsed Laser ◽  
Green Emission ◽  
Biological Imaging ◽  
Additive Concentration ◽  
Uniform Size ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Diagnostic Applications ◽  
Ceramic Targets ◽  
Co Doped

As diagnostic biosensors for analyzing fluids from the human body, the development of inorganic NPs is of increasing concern. For one, nanoceramic phosphors have been studied to meet the increasing requirements for biological, imaging, and diagnostic applications. In this study, Y2O3 NPs co-doped with trivalent rare earths (erbium and ytterbium) were obtained using a liquid phase–pulsed laser ablation (LP–PLA) method after getting high density Er, Yb:Y2O3 ceramic targets by Spark plasma sintering (SPS). Most NPs are under 50 nm in diameter and show high crystallinity of cubic Y2O3 structure, containing (222), (440), and (332) planes via HR–TEM. Excitation under a 980 nm laser to a nanoparticle solution showed 525 and 565 nm green, and 660 nm red emissions. The green emission intensity increased and decreased with increasing Yb3+ additive concentration, when the red spectrum continuously strengthened. Utilizing this study’s outcome, we suggest developing technology to mark invisible biomolecules dissolved in a solvent using UC luminescence of Er3+, Yb3+ co-doped Y2O3 NPs by LP–PLA. The LP–PLA method has a potential ability for the fabrication of UC NPs for biosensors with uniform size distribution by laser parameters.

Enhanced green emission from Tb3+–Bi3+ co-doped GdAlO3 nanophosphors

2010 ◽  
Vol 45 (5) ◽  
pp. 572-575 ◽  
Author(s):  
Jin Young Park ◽  
Hong Chae Jung ◽  
G. Seeta Rama Raju ◽  
Byung Kee Moon ◽  
Jung Hyun Jeong ◽  
...  
Keyword(s):  
Green Emission ◽  
Co Doped

ORGANIC CuPc COATING INDUCED IMPROVED PHOTOLUMINESCENCE AND PHOTOCONDUCTIVITY OF ZnO NANOWIRES ARRAY

2012 ◽  
Vol 05 (03) ◽  
pp. 1250021 ◽  
Author(s):  
SOUMEN DHARA ◽  
P. K. GIRI
Keyword(s):  
Charge Transfer ◽  
Dark Current ◽  
Surface Defects ◽  
Green Emission ◽  
Charge Transfer Process ◽  
Current Ratio ◽  
Uv Emission ◽  
Surface Covering ◽  
Interfacial Charge ◽  
Nanowires Array

In this work, we investigated the effect of organic CuPc coating on the surface of the ZnO NWs for possible improvement in the photoluminescence, photoconductivity and photoresponse. As a result of surface covering, the UV emission is enhanced by a factor of 7–8 while the green emission is reduced to half. Despite an increase in dark current after the CuPc covering, we obtained a significant improvement in the photocurrent and photoresponse rate. The photocurrent-to-dark current ratio is nearly doubled and the photoresponse process becomes faster for the ZnO/CuPc heterostructure. Improvements in the photoluminescence and photoconductivity for the ZnO/CuPc heterostructure are explained on the basis of modification of surface defects and interfacial charge transfer process.

A novel tunable blue-green-emitting CaGdGaAl2O7:Ce3+,Tb3+ phosphor via energy transfer for UV-excited white LEDs

2015 ◽  
Vol 44 (17) ◽  
pp. 8100-8106 ◽  
Author(s):  
Chao Liang ◽  
Hongpeng You ◽  
Yibing Fu ◽  
Xiaoming Teng ◽  
Kai Liu ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Green Emission ◽  
Relative Content ◽  
White Leds

By tuning the relative content of the doped ions, tunable blue-green emission can be obtained by irradiation at 365 nm.

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