Tuning of the Structure and Emission Spectra of Upconversion Nanocrystals by Alkali Ion Doping

Langmuir ◽  
2011 ◽  
Vol 27 (21) ◽  
pp. 13236-13241 ◽  
Author(s):  
Qingqing Dou ◽  
Yong Zhang
Keyword(s):  
Emission Spectra ◽  
Upconversion Nanocrystals ◽  
Ion Doping ◽  
Alkali Ion

Controlled synthesis of luminescent Gd2O3:Eu3+nanoparticles by alkali ion doping

CrystEngComm ◽  
2015 ◽  
Vol 17 (9) ◽  
pp. 1997-2003 ◽  
Author(s):  
Dominika Wawrzynczyk ◽  
Marek Samoć ◽  
Marcin Nyk
Keyword(s):  
Controlled Synthesis ◽  
Ion Doping ◽  
Alkali Ion

scholarly journals Distinct Impact of Alkali-Ion Doping on Electrical Transport Properties of Thermoelectric p-Type Polycrystalline SnSe

2016 ◽  
Vol 138 (28) ◽  
pp. 8875-8882 ◽  
Author(s):  
Tian-Ran Wei ◽  
Gangjian Tan ◽  
Xiaomi Zhang ◽  
Chao-Feng Wu ◽  
Jing-Feng Li ◽  
...  
Keyword(s):  
Transport Properties ◽  
Electrical Transport ◽  
Electrical Transport Properties ◽  
Ion Doping ◽  
P Type ◽  
Alkali Ion

Influence of alkali ion doping on the electrochemical performances of tin-based composite materials

2010 ◽  
Vol 195 (10) ◽  
pp. 3316-3322 ◽  
Author(s):  
A. Aboulaich ◽  
D.E. Conte ◽  
J. Olivier-Fourcade ◽  
C. Jordy ◽  
P. Willmann ◽  
...  
Keyword(s):  
Composite Materials ◽  
Electrochemical Performances ◽  
Ion Doping ◽  
Alkali Ion

scholarly journals Photoluminescent Spectra of Nd3+Codoped CaAl2O4:Eu2+Blue Phosphor

2007 ◽  
Vol 2007 ◽  
pp. 1-4 ◽  
Author(s):  
Hojin Ryu ◽  
K. S. Bartwal
Keyword(s):  
Electron Microscopy ◽  
Emission Spectra ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Phosphor Material ◽  
Long Afterglow ◽  
Blue Phosphor ◽  
Transmission Electron ◽  
Ion Doping ◽  
Synthesized Materials

Phosphor material CaAl2O4:Eu2+codoped with varying concentrations ofNd3+was prepared by solid-state reaction method. Prepared materials with 1 mol%Eu2+andNd3+(0.5 to 5 mol%) show high brightness and long persistent luminescence. The phase and crystallinity of the synthesized materials were investigated by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Photoluminescence excitation and emission spectra were taken to investigate the luminescence characteristics. Broadband UV excited luminescence of the CaAl2O4:Eu2+,Nd3+was observed in the blue region (λmax= 440 nm) due to transitions from4f 6 5d1to the4f 7configuration of theEu2+ion. TheNd3+ion doping in the phosphor generates deep traps which result in long afterglow phosphorescence.

Engineering the electronic structure and optical properties of g-C3N4 by non-metal ion doping

2016 ◽  
Vol 4 (28) ◽  
pp. 6839-6847 ◽  
Author(s):  
Qianyi Guo ◽  
Yuanhao Zhang ◽  
Jianrong Qiu ◽  
Guoping Dong
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Metal Ions ◽  
Metal Ion ◽  
Carbon Nitride ◽  
Emission Spectra ◽  
Ion Doping ◽  
Pl Emission

The normalized PL emission spectra of graphite-like carbon nitride (g-C3N4) modified with different non-metal ions (boron and sulfur) exhibit interesting scientific variation.

Alkali ion doping of silicon

1964 ◽  
Vol 52 (3) ◽  
pp. 301-302 ◽  
Author(s):  
J.O. McCaldin ◽  
A.E. Widmer
Keyword(s):  
Ion Doping ◽  
Alkali Ion

scholarly journals Upconversion Nanocrystal Doped Polymer Fiber Thermometer

Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6048
Author(s):  
Jonas Thiem ◽  
Simon Spelthann ◽  
Laurie Neumann ◽  
Florian Jakobs ◽  
Hans-Hermann Johannes ◽  
...  
Keyword(s):  
Thermal Emission ◽  
Thermal Sensitivity ◽  
Active Material ◽  
Emission Spectra ◽  
Polymer Fibers ◽  
Attractive Alternative ◽  
Polymer Fiber ◽  
Upconversion Nanocrystals ◽  
Emission Changes ◽  
Doped Polymer

In recent years, lanthanide-doped nanothermometers have been mainly used in thin films or dispersed in organic solvents. However, both approaches have disadvantages such as the short interaction lengths of the active material with the pump beam or complicated handling, which can directly affect the achievable temperature resolution. We investigated the usability of a polymer fiber doped with upconversion nanocrystals as a thermometer. The fiber was excited with a wavelength stabilized diode laser at a wavelength of 976 nm. Emission spectra were recorded in a temperature range from 10 to 35 ∘C and the thermal emission changes were measured. Additionally, the pump power was varied to study the effect of self-induced heating on the thermometer specifications. Our fiber sensor shows a maximal thermal sensitivity of 1.45%/K and the minimal thermal resolution is below 20 mK. These results demonstrate that polymer fibers doped with nanocrystals constitute an attractive alternative to conventional fluorescence thermometers, as they add a long pump interaction length while also being insensitive to strong electrical fields or inert to bio-chemical environments.

Controllable Luminescent Properties of Phosphors Sr2.97-XCaxMgSi2O8: Eu0.012+, Dy0.023+ by Adjusting Sr/Ca Ratio

2010 ◽  
Vol 663-665 ◽  
pp. 118-124
Author(s):  
Jun Fu Chu ◽  
Yi Hua Hu ◽  
Hai Wang Yin ◽  
Yi Wu Hao
Keyword(s):  
Size Variation ◽  
Emission Spectra ◽  
Luminescent Properties ◽  
Crystal Defects ◽  
Co Doping ◽  
Long Afterglow ◽  
Ion Doping ◽  
Ca Ions ◽  
Small Change ◽  
Reductive Atmosphere

Divalent europium and trivalent dysprosium co-doping in the compounds Sr2.97-xCaxMgSi2O8 (x=0, 0.5, 1.5, 2, 2.5, 2.97) produces phosphors of high luminescence yield. These phosphors were prepared at high temperature and weak reductive atmosphere. The ratio of Eu/Dy is 1/2. The phosphors were characterized for their crystal phases by x-ray powder diffraction. Slight shifts of the peaks in the structure, which indicate a small change of the interplanar crystal spacing, were observed for each different x’s. The interplanar spacing becomes narrow as increasing the value of x. These phosphors respond well to the ultraviolet excitation. The peak of the emission band occurs at progressively longer wavelength and widens as the ratio of alkaline earth Sr/Ca ions is decreased. The emission peaks of the phosphors indicated on the emission spectra range from 463nm to 490nm. It is probably due to the influence of 5d electron states of Eu2+ in the crystal field because of atomic size variation causing crystal defects. Dy3+ ion doping in the phosphor generates deep traps, which results in long afterglow phosphorescence. As the proportion of Ca in the composition increases, the attenuation time of the phosphors becomes short.

Nano-probe x-ray analysis and high-resolution imaging on planar defects in high-pressure synthesized infinite-layer superconductor

1994 ◽  
Vol 52 ◽  
pp. 728-729
Author(s):  
Y. Y. Wang ◽  
H. Zhang ◽  
V. P. Dravid ◽  
H. Zhang ◽  
L. D. Marks ◽  
...  
Keyword(s):  
High Pressure ◽  
High Resolution ◽  
Atomic Structure ◽  
Emission Spectra ◽  
High Resolution Electron Microscopy ◽  
Planar Defects ◽  
X Ray ◽  
Infinite Layer ◽  
Resolution Electron ◽  
Resolution Imaging

Azuma et al. observed planar defects in a high pressure synthesized infinitelayer compound (i.e. ACuO2 (A=cation)), which exhibits superconductivity at ~110 K. It was proposed that the defects are cation deficient and that the superconductivity in this material is related to the planar defects. In this report, we present quantitative analysis of the planar defects utilizing nanometer probe xray microanalysis, high resolution electron microscopy, and image simulation to determine the chemical composition and atomic structure of the planar defects. We propose an atomic structure model for the planar defects.Infinite-layer samples with the nominal chemical formula, (Sr1-xCax)yCuO2 (x=0.3; y=0.9,1.0,1.1), were prepared using solid state synthesized low pressure forms of (Sr1-xCax)CuO2 with additions of CuO or (Sr1-xCax)2CuO3, followed by a high pressure treatment.Quantitative x-ray microanalysis, with a 1 nm probe, was performed using a cold field emission gun TEM (Hitachi HF-2000) equipped with an Oxford Pentafet thin-window x-ray detector. The probe was positioned on the planar defects, which has a 0.74 nm width, and x-ray emission spectra from the defects were compared with those obtained from vicinity regions.

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