• Title/Summary/Keyword: luminescence enhancement

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A New Analytical Method for the $Dy^{3+}$ Ion Using the Luminescence Enhancement by the Treatment of o-Phenanthroline on the TLC Plate (TLC Plate에서의 발광증폭 및 o-Phenanthroline에 의한 Energy Transfer를 이용한 $Dy^{3+}$ 이온의 미량 분석법)

  • Jeong, Hyuk
    • Analytical Science and Technology
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    • v.11 no.5
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    • pp.386-393
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    • 1998
  • A new analytical luminescence method for the $Dy^{3+}$ ion was studied using the luminescence enhancement by the treatment of the o-phenanthroline on the TLC plate. Compared to the specific emission intensities of the ion in water solution, if the ion solution is spotted on the TLC plate, the luminescence intensities were extremely enhanced. There was additional enhancement effect of the luminescence intensities of the ions on the TLC plate, if the ion on the TLC plate is treated with o-phenanthroline. Based on the luminescence enhancement, the detection limit was improved by more than 4 order of magnitude compared to that of solution sample. The dynamic ranges and correlation coefficients of the calibration curves near the detection limit were 102 order and ~0.99, respectively. The energy-transfer mechanism was explained for the theoretical back ground of the luminescence enhancement.

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A New Analytical Method for the $Eu^{+3}$ and $Tb^{+3}$ Ions Using the Luminescence Enhancement by the Treatment of o-Phenanthroline on the Nylon Membrane (Nylon Membrane Filter에서의 발광증폭을 이용한 $Eu^{+3}$$Tb^{+3}$ 이온의 극미량 분석법)

  • An, Seong-Hee;Lee, Byung-Min;Park, Jong-Mok;Kim, Hai-Dong;Jeong, Hyuk
    • Journal of the Korean Chemical Society
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    • v.39 no.9
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    • pp.705-714
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    • 1995
  • A new analytical luminescence method for the Eu+3 and Tb+3 ions was studied using the luminescence enhancement by the treatment of the o-phenanthroline on the nylon membrane. Compared to the specific emission intensities of the ions in aqueous(or ethanol) solution, if the aqueous ion is spotted on the nylon membrane, the luminescence intensities were extremely enhanced. There was additional enhancement effect of the luminescence intensities of the ions on the nylon membrane, if the ion on the nylon membrane is treated with o-phenanthroline. Based on the luminescence enhancement, the detection limits were lowered by more than 7 order of magnitude compared to that of solution sample, and also lowered by about 1 order of magnitude compared to that of previous TLC method. The dynamic ranges and correlation coefficients of the calibration curves near the detection limit were 2∼3 order and ∼0.99, respectively. It was also shown that the luminescence intensity was in its maximum when the ion on the nylon is treated with ∼4 mole ratio of o-phenanthroline. The energy-transfer mechanism was explained for the theoretical background of the luminescence enhancement.

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Enhanced Cathode-Luminescence in a InxGa1-xN/InyGa1-y Green Light Emitting Diode Structure Using Two-Dimensional Photonic Crystals

  • Choi, Eui-Sub;Lee, Jae-Jin
    • Journal of Electrical Engineering and Technology
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    • v.3 no.2
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    • pp.276-279
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    • 2008
  • We report on the enhancement of cathode-luminescence in an $In_xGa_{1-x}N/In_yGa_{1-y}$ green light emitting diode structure using two-dimensional photonic crystals. The square lattice arrays of photonic crystals with diameter/periodicity of 200/500 nm were fabricated by electron beam lithography. Inductively coupled plasma dry etching was used to etch and define photonic crystals. Three samples with different etch depths, i.e., 170, 95, and 65 nm, were constructed. Field emission scanning electron microscope analysis shows that air holes of photonic crystal structure with inverted-cone shapes were fabricated after dry etching. Cathode-luminescence measurement indicated that up to 30-fold enhancement of cathode-luminescence intensity has been achieved.

A New Analytical Method for the $Tb^{+3}$ and $Eu^{+3}$ Ions Using the Fluorescence Enhancement on the TLC Plate (TLC상에서의 형광증폭을 이용한 $Tb^{+3}$$Eu^{+3}$ 이온의 미량분석에 관한 연구)

  • Jeong, Hyuk;Lee, Gee-Yeoun;An, Seong-Hee;Kim, Hai-Dong;Lee, Won;Shin, Dae-Ho
    • Journal of the Korean Chemical Society
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    • v.39 no.1
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    • pp.40-46
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    • 1995
  • A new analytical luminescence method for the Tb+3 and Eu+3 ions was studied using the fluorescence enhancement of the ions on the TLC plate. Compared to the specific emission intensities of the ions in aqueous or ethanol solution, if spotted on the TLC plate, the line intensities were extremely enhanced. There was additional enhancement effect of the lines from the ions on the TLC plate, if treated with ο-phenanthroline. Based on the luminescence enhancement, the detection limit of the ions was lowered more than 6 order of magnitude compared to the luminescence method using solution samples. The energy-transfer mechanism was also explained for the theoretical back ground of the luminescence enhancement.

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Synthesis and Luminescence Properties of CaS:Eu2+,Si4+,Ga3+ for a White LED

  • Oh, Sung-Il;Jeong, Yong-Kwang;Kang, Jun-Gill
    • Bulletin of the Korean Chemical Society
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    • v.30 no.2
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    • pp.419-422
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    • 2009
  • The luminescence intensity of calcium sulfide codoped with $Eu^{2+},\;Si^{4+}\;and\;Ga^{3+}$ was investigated as a function of the dopant concentration. An enhancement of the red luminescence resulted from the incorporation of $Si^{4+}\;and\;Ga^{3+}\;into\;CaS:Eu^{2+}.\;The\;non-codoped\;CaS:Eu^{2+}$ converted only 3.0% of the absorbed blue light into luminescence. As the $Si^{4+}\;and\;Ga^{3+}$ were embedded into the host lattice, the luminescence intensity increased and reached a maximum of Q = 10.0% at optimized concentrations of the codopants in CaS. Optimized CaS:$Eu^{2+},Si^{4+},Ga^{3+}$ phosphors were fabricated with blue GaN LED and the chromaticity index of the phosphor-formulated GaN LED was investigated as a function of the wt% of the optimized phosphor.

Photoluminescence Enhancement of Y2O3:Eu3+ Red Phosphor Prepared by Spray Pyrolysis using Aliovalent Cation Substitution and Organic Additives (이가 양이온 금속 친환 및 유기 첨가제를 이용하여 분무열분해법으로 제조된 Y2O3:Eu3+ 적색 형광체의 휘도 개선)

  • Min, Byeong Ho;Jung, Kyeong Youl
    • Journal of Powder Materials
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    • v.27 no.2
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    • pp.146-153
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    • 2020
  • The co-doping effect of aliovalent metal ions such as Mg2+, Ca2+, Sr2+, Ba2+, and Zn2+ on the photoluminescence of the Y2O3:Eu3+ red phosphor, prepared by spray pyrolysis, is analyzed. Mg2+ metal doping is found to be helpful for enhancing the luminescence of Y2O3:Eu3+. When comparing the luminescence intensity at the optimum doping level of each Mg2+ ion, the emission enhancement shows the order of Zn2+ ≈ Ba2+ > Ca2+ > Sr3+ > Mg2+. The highest emission occurs when doping approximately 1.3% Zn2+, which is approximately 127% of the luminescence intensity of pure Y2O3:Eu3+. The highest emission was about 127% of the luminescence intensity of pure Y2O3:Eu3+ when doping about 1.3% Zn2+. It is determined that the reason (Y, M)2O3:Eu3+ has improved luminescence compared to that of Y2O3:Eu3+ is because the crystallinity of the matrix is improved and the non-luminous defects are reduced, even though local lattice strain is formed by the doping of aliovalent metal. Further improvement of the luminescence is achieved while reducing the particle size by using Li2CO3 as a flux with organic additives.

Highly Sensitive Luminescence Assessment of Bile Acid Using a Balofloxacin-Europium(III) Probe in Micellar Medium

  • Cai, Huan;Zhao, Fang;Si, Hailin;Zhang, Shuaishuai;Wang, Chunchun;Qi, Peirong
    • Bulletin of the Korean Chemical Society
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    • v.33 no.12
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    • pp.4145-4149
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    • 2012
  • A novel and simple method of luminescence enhancement effect for the determination of trace amounts of bile acid was proposed. The procedure was based on the luminescence intensity of the balofloxacin-europium(III) complex that could be strongly enhanced by bile acid in the presence of sodium dodecyl benzene sulfonate (SDBS). Under the optimum conditions, the enhanced luminescence intensity of the system exhibited a good linear relationship with the bile acid concentration in the range $5.0{\times}10^{-9}-7.0{\times}10^{-7}\;mol\;L^{-1}$ with a detection limit of $1.3{\times}10^{-9}\;mol\;L^{-1}$ ($3{\sigma}$). The relative standard deviation (RSD) was 1.7% (n = 11) for $5.0{\times}10^{-8}\;mol\;L^{-1}$ bile acid. The applicability of the method to the determination of bile acid was demonstrated by investigating the effect of potential interferences and by analyzing human serum and urine samples. The possible enhancement mechanism of luminescence intensity in balofloxacin-europium(III)-bile acid-SDBS system was also discussed briefly.

Luminescence Enhancement by Ba in SrTiO3:Pr, Al Red Phosphor for Field Emission Displays

  • Won, Chang-Whan;Lee, Jong-Eun;Won, Hyung-Il;Kim, Kwang-Bok;Song, Yoon-Ho;Kang, Seung-Youl;Koo, Kyoung-Wan
    • Journal of the Korean Ceramic Society
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    • v.43 no.11 s.294
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    • pp.743-745
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    • 2006
  • The luminescence properties of $Sr_{1-x}Ba_xTiO_3:Pr$, Al red phosphor for Field Emission Displays (FEDs) have been investigated in powders prepared though solid-state reactions. $Sr_{1-x}Ba_xTiO_3:Pr$, Al red phosphors indicate a higher luminescent intensity, and have been found to have potential for field emission displays. The addition of Ba increased the luminescence intensity at 617 nm by up to 30%. Ba ions are effective in producing the energy transfers from host-to-activator in 4f-5d transitions.