• Title/Summary/Keyword: 휘도의 균일도

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Photoluminescent properties of red phosphor (Y,Gd)$_2$O$_3$: Eu for plasma display panel synthesized by homogeneous precipitation method (균일침전법으로 제조한 플라즈마 디스플레이용 적색 형광체 (Y,Gd)$_2$O$_3$: Eu의 발광특성)

  • 김유혁;김좌연
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.10 no.6
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    • pp.400-406
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    • 2000
  • The fired Precursor (Y,Gd,Eu)(OH)$CO_3$.$H_2O$$900^{\circ}C$ was used to synthesize the red phosphor $(Y,Gd)_2O_3$: Eu for plasma display panel. Rounded and ~l $\mu\textrm{m}$ diameter phosphor $(Y,Gd)_2O_3$: Eu can be obtained by the reaction of aformentioned powder with a small amount addition of flux at $1350^{\circ}C$ for 2 hours. Emission spectra of these phosphors were measured under excitation wavelength at 254 nm and 147 nm and the optimum concentrations of activator ion were determined at around 15 mo1e % and 10 mole % under these conditions, respectively. $BaCO_3$flux had the best property in emission intensity among the prepared $BaCO_3AlF_3$and $Li_3PO_4$phosphors. The properties of optimized sample were improved in terms of relative luminance and color coordinate comparing with commercial phosphor such as $Y_2O_3$: Eu.

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Fabrication and Device Characteristics of Infrared Photodetector Based on InAs/GaSb Strained-Layer Superlattice (InAs/GaSb 응력초격자를 이용한 적외선검출소자의 제작 및 특성 연구)

  • Kim, J.O.;Shin, H.W.;Choe, J.W.;Lee, S.J.;Kim, C.S.;Noh, S.K.
    • Journal of the Korean Vacuum Society
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    • v.18 no.2
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    • pp.108-115
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    • 2009
  • The superlattice infrared photodetector (SLIP) with an active layer of 8/8-ML InAs/GaSb type-II strained-layer superlattice (SLS) of 150 periods was grown by MBE technique, and the proto-type discrete device was defined with an aperture of $200-{\mu}m$ diameter. The contrast profile of the transmission electron microscope (TEM) image and the satellite peak in the x-ray diffraction (XRD) rocking curve show that the SLS active layer keeps abrupt interfaces with a uniform thickness and a periodic strain. The wavelength and the bias-voltage dependences of responsivity (R) and detectivity ($D^*$) measured by a blackbody radiation source give that the cutoff wavelength is ${\sim}5{\mu}m$, and the maximum Rand $D^*$ ($\lambda=3.25{\mu}m$) are ${\sim}10^3mA/W$ (-0.6 V/13 K) and ${\sim}10^9cm.Hz^{1/2}/W$ (0 V/13 K), respectively. The activation energy of 275 meV analyzed from the temperature dependent responsivity is in good agreement with the energy difference between two SLS subblevels of conduction and valence bands (HH1-C) involving in the photoresponse process.

A Study on Photoluminance Properties of $(Y,Gd)BO_3:Eu^{3+}$ Phosphor Synthesized by Ultrasonic Spray Pyrolysis (초음파 분무법으로 제조한 $(Y,Gd)BO_3:Eu^{3+}$ 형광체의 발광특성에 관한 연구)

  • Kim, Dae-Su;Lee, Rhim-Youl
    • Korean Journal of Materials Research
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    • v.10 no.3
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    • pp.204-211
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    • 2000
  • The $(Y,Gd)BO_3:Eu$ red phosphors for PDP application were synthesized by ultrasonic spray method and then their photoluminance properties were investigated under 147nm VUV irradiation. The precursor solution of acetates of Y, GD and Eu and boric acid diluted in water was sprayed using 1.7 MHz ultra-sonic sprayer into the reaction tube held at high temperature. The as-sprayed particles were amorphous phase having C-C and C-H bonds due to the insufficient thermal reaction during the pass along the tube. But the sprayed samples followed by heat treatment at $1100^{\circ}C$ had the same crystal structure and chemical composition as those samples followed by solid state reaction. It was found that the $(Y_{0.7}Gd_{0.3})_{0.95} BO_3:Eu_{0.05}^{3+}$ phosphor particles synthesized by spray at $500^{\circ}C$ and then heat treated at $900^{\circ}C$ had a spherical-like shape and fine particle size at $0.7{\mu\textrm{m}}$ having a narrow size distribution, while the phosphor particles made by solid state reaction was $3{\mu\textrm{m}}$ coarse and non-uniform size distribution. The emitting intensity under 147nm VUV excitation for $(Y_{0.7}Gd_{0.3})_{0.95}BO_3:Eu_{0.05}^{3+}$ phosphor prepared by spray method was found to be higher than those phosphor made by solid state reaction and the commercial $(Y,Gd)BO_3:Eu$ product.

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Fine Size YAG:Tb Phosphor Particles Prepared by Spray Pyrolysis (분무 열분해 공정에 의해 합성된 미세 YAG:Tb 형광체)

  • Lee, Hyo Jin;Hong, Seung Kwon;Jung, Dae Soo;Kang, Yun Chan;Jung, Kyeong Youl
    • Korean Chemical Engineering Research
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    • v.43 no.3
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    • pp.407-411
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    • 2005
  • YAG:Tb($Y_3Al_5O_{12}:Tb$) phosphor particles were prepared by spray pyrolysis from spray solution containing various types of flux materials. The effects of type of flux, organic material and post-treatment temperature on the characteristics of morphology, crystallinity and photoluminescence of YAG:Tb phosphor particles were investigated. Citric acid and ethylene glycol used as organic additive improved the photoluminescence intensity of the YAG:Tb phosphor particles without destruction of the morphology after post-treatment at high temperature. However, the spherical shape of the precursor particles obtained by spray pyrolysis from spray solution containing high amount of flux material disappeared after post-treatment at $1300^{\circ}C$. YAG:Tb phosphor particles prepared from spray solution containing lithium carbonate flux had fine size and regular morphology after post-treatment. Lithium carbonate used as flux material was also efficient in improvement of the photoluminescence intensity of the YAG:Tb phosphor particles. The optimum photoluminescence intensity of the YAG:Tb phosphor particles prepared from spray solution containing lithium carbonate flux was 189% of that of the phosphor particles prepared from spray solution without flux material.