Near-Infrared-to-Green Upconversion in Yb3+/Er3+ Co-Doped BaYF5 by Chemical Co-Precipitation Method

2010 ◽  
Vol 663-665 ◽  
pp. 328-331 ◽  
Author(s):  
Hai Yan Du ◽  
Wei Hang Zhang ◽  
Jia Yue Sun
Keyword(s):  
Optical Properties ◽  
Laser Diode ◽  
Near Infrared ◽  
Precipitation Method ◽  
Structural And Optical Properties ◽  
Solution Processed ◽  
Co Precipitation ◽  
Barium Yttrium ◽  
Co Doped

Barium yttrium fluorides ( BaYF5 ) co-doped with Er3+ and Yb3+ were synthesized by the chemical co-precipitation method and the structural and optical properties of solution-processed Er3+/Yb3+ co-doped BaYF5 were characterized. Intense visible emissions centered at around 523, 546 and 658 nm, originated from the transitions of 2H11/2 → 4I15/2, 4S3/2 → 4I15/2, and 4F9/2 → 4I15/2 of Er3+, respectively, have been observed in samples upon excitation with a 980nm laser diode, and the involved mechanisms have been explained.

Synthesis of mesoporous Fe-Mn bimetal oxide nanocomposite by aeration co-precipitation method: Physicochemical, structural, and optical properties

2019 ◽  
Vol 224 ◽  
pp. 65-72 ◽  
Author(s):  
Hadi Eslami ◽  
Mohammad Hassan Ehrampoush ◽  
Abbas Esmaeili ◽  
Ali Asghar Ebrahimi ◽  
Mohammad Taghi Ghaneian ◽  
...  
Keyword(s):  
Optical Properties ◽  
Precipitation Method ◽  
Structural And Optical Properties ◽  
Co Precipitation

Synthesis and Optical Properties of Annealed Cr Doped ZnS Nanoparticles

2013 ◽  
Vol 678 ◽  
pp. 163-167 ◽  
Author(s):  
D. Amaranatha Reddy ◽  
G. Murali ◽  
N. Madhusudhana Rao ◽  
R.P. Vijayalakshmi ◽  
B.K. Reddy
Keyword(s):  
Optical Properties ◽  
Hexagonal Phase ◽  
Blue Emission ◽  
Precipitation Method ◽  
Cubic Phase ◽  
Structural And Optical Properties ◽  
Zns Nanoparticles ◽  
Blue Emission Peak ◽  
Co Precipitation ◽  
Surface Morphologies

Undoped and Cr doped ZnS nanoparticles with Cr concentrations of 3.0 at.% were prepared by a chemical co-precipitation method for the fist time, using 2-Mercaptoethanol as the capping agent and annealed the synthesized particles at 600°C for 3h in air. The effect of annealing on morphological, structural and optical properties of ZnS and ZnS:Cr have been studied and compared with as prepared samples. EDAX measurements confirmed the presence of Cr in the ZnS lattice and it also confirms the conversion of ZnS into ZnO after annealed at 600 0C/3h. Surface morphologies of all samples were characterized using scanning electron microscopy (SEM). XRD spectra of as synthesized nanoparticles of ZnS and ZnS:Cr exhibited cubic phase. After annealing, the cubic phase is transformed into hexagonal phase. The particle sizes of the ZnS:Cr powders were increased from 5 to 30 nm when the powders were annealed at 600°C. A stable blue emission peak at 445 nm is observed from the as prepared samples (pure ZnS and Cr doped ZnS) but annealed at 600 0C the PL peaked at 500 nm for pure ZnS and Cr doped ZnS nanoparticles exhibited PL peak at 500 nm as well as 654 nm. The emission intensity decreased in annealed particles compared to as synthesized samples.

Effect of Cobalt Dopant on Structural and Optical Properties of Co-Precipitated TiO2 Nanopowders

2016 ◽  
Vol 675-676 ◽  
pp. 97-100 ◽  
Author(s):  
Prasopporn Junlabhut ◽  
Chakkaphan Wattanawikkam ◽  
Weerachon Phoohinkong ◽  
Wanichaya Mekprasart ◽  
Wisanu Pecharapa
Keyword(s):  
Optical Properties ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Visible Region ◽  
Precipitation Method ◽  
Tetrabutyl Titanate ◽  
Chemical Compositions ◽  
Nitrate Hexahydrate ◽  
Structural And Optical Properties ◽  
Co Doped

The effects of cobalt (Co) addition on structural and optical properties of TiO2 nanopowders have been investigated. A co-precipitation method was employed to synthesize TiO2 nanoparticles with various Co additives from 0-10 mol% using tetrabutyl titanate and Cobalt (II) nitrate hexahydrate as starting precursors for Ti and Co source, respectively. The crystallinity of Co-doped TiO2 nanopowders is heightened by calcination process. The crystal structure, phase formation and the corresponding functional groups of Co-doped TiO2 were analyzed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The scanning electron microscope (SEM) was taken to observe their morphologies. The chemical compositions of Co additive into TiO2 matrix are confirmed by EDAX. Their optical properties were investigated by diffuse reflectance spectroscopy. Diffuse reflectance spectra of samples exhibit the increasing absorption in visible region with an increasing Co content. The overall characterization results indicated that the crystallinity and optical properties of TiO2 nanoparticles are significantly affected by Co dopant.

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