• Title/Summary/Keyword: Luminescene

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Preparation and Luminescene properties with invisible inoranic phosphors of nano size (나노크기의 비가시 무기형광체 제조와 발광특성)

  • Jeong, Jae-Hoon;Yun, Hyun;Jang, Gyu-Hwan;Shin, Sang-Sik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.461-462
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    • 2008
  • $BaMgAl_{10}O_{17}$:Mn, $Eu^{2+}$ green phosphors has been synthesized by the solid state reaction. Green phosphors of nano-size were manufactured in short time by shake method. which were easily manufactured respectively general method. Green phosphors of nano size were control additive, size of $ZrO_3$ ball, shake time and weight of ball in toluene. In result that green phosphors were obtained particle size of 140nm~150nm. The characteristics of fired samples were obtained by 365nm and 380nm excitation source under ultraviolet. In result that the highest PL intensity were observed in wavelength of 365nm.

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Pulsed Photostimulated Luminescence of Irradiated Black and White Peppers and Effects of Long-Term Storage

  • Oh, Man-Jin;Yi, Sang-Duk;Jeoung, Hyun-Kyo;Chang, Kyu-Seob;Yang, Jae-Seung;Song, Chi-Kwang
    • Preventive Nutrition and Food Science
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    • v.7 no.2
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    • pp.195-200
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    • 2002
  • Changes in accumulated pulsed photostimulated luminescene (PPSL) signals were observed after storage, which affected the ability to detect irradiation in black and white peppers. The PPSL curves were accumulated linearly during the 120 s measurement times, and PPSL signals increased according to irradiation doses. Threshold levels of black and white peppers were below 557$\pm$220 and 503$\pm$92 photon counts in 60 s, and below 679$\pm$351 and 812 $\pm$ 648 photon counts in 120 s, respectively. The PPSL signals of black and white peppers linearly increased with irradiation dose up to 5 kGy, but very little from 5~10 kCy. The accumulated PPSL signals of irradiated black and white peppers had higher decay rates when stored in normal room conditions than in a darkroom Detection of irradiation was possible for up to 12 months after irradiation, if the samples were stored in a darkroom.

Properties and Peculiar Features of Application of Isoelectronically Doped $A^2B^6$ Compound-Based Scintillators

  • Ryzhikov, V.;Starzhinskiy, N.
    • Journal of Radiation Protection and Research
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    • v.30 no.2
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    • pp.77-84
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    • 2005
  • The authors submit the data concerning the methods of obtaining semiconductor scintillators on the basis of the zinc chalcogenide crystal doped with impurities (Te, Cd, O, $Me^{III}-metals$ Al, In, etc.). Characteristics of such crystals and mechanisms for the semiconductor scintillator luminescence are described as well. The scintillator luminescence spectra maximums are located within the range 450-640nm, which depends on the method of preparing the scintillator. The luminescence decay time ranges within $0.5-10{\mu}s\;and\;30-150{\mu}s$. The afterglow level is less than 0.01% after $10-20{\mu}s$, and the radiation stability is ${\geq}5{\cdot}10^8$ rad. Thermostability of the output characteristics of new semiconductor scintillators on the basis of zinc selenide is prescribed by thermodynamic stability of the principal associative radiative recombination centers that come into existence due to the crystal lattice inherent imperfections. Certain application fields of the new scintillators are examined taking into account their particular qualities.

ZnNiO thin films deposited by r.f. magnetron sputtering method (RF Magnetron Sputtering법으로 증착된 ZnNiO박막의 특성)

  • 오형택;이태경;김동우;박용주;박일우;김은규
    • Journal of the Korean Vacuum Society
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    • v.12 no.4
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    • pp.269-274
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    • 2003
  • The electrical, optical and structural properties of ZnNiO thin _ films deposited on Si substrates using rf-magnetron sputtering method have been investigated before and after the thermal annealing processes. The crystallinity of the ZnNiO thin film become degraded with increasing the Ni contents. This is mainly because the lattice of the thin film was expanded due to the oxygen-deficient conditions. Concerning the electrical properties of the thin film, the carrier concentration increases ($6.81\times10^{14}\textrm{cm}^{-2}$) and Hall mobility decreases (36.3 $\textrm{cm}^2$/Vㆍs) with higher doping concentration of Ni. However, the carrier concentration and Hall mobility became low ($1.10\times10^{14}\textrm{cm}^2$ and high (209.6 $\textrm{cm}^2$/Vㆍs), respectively, after the thermal annealing process at $1000 ^{\circ}C$. We also observed a strong luminescene center peaking at 546 nm in photoluminescence spectra, which was caused by a deep level center in the ZnO band gap with oxygen deficient ZnNiO structure.