• Title, Summary, Keyword: ${Y_2}{SiO_5}:Ce$

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Li-doped Y2SiO5:Ce, Blue-emitting Phosphor (Li-이온이 도핑된 Y2SiO5:Ce 청색 형광체)

  • Park, Jung-Cheol;Jeon, Gi-Wan
    • Journal of the Korean Chemical Society
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    • v.50 no.3
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    • pp.232-236
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    • 2006
  • The Y1.99-xMxCe0.01SiO5(M=Li, La, Nd, and Gd) phosphors were synthesized by solid-state reaction at 1350oC for 10h under reducing atmosphere in order to improve properties of blue emitting phosphors. Compared with commercial blue phosphors, the Y2SiO5:Ce blue phosphors substituted with various elements showed significant enhancement of the emission intensity. Particularly, 1 mol% Li doped Y2SiO5:Ce phosphors indicated the maximum emission intensity in the photoluminescence spectra. Thanks to SEM analyses revealed that the morphology of Y2SiO5:(Ce,Li) blue phosphors was a pseudo-spherical with particle size of 3m.

Properties of $Y_{2-x}SiO_{5}:Ce_{x}^{3+}$ Phosphor Powder Prepared by Sol-gel Process (Sol-gel법에 의한 $Y_{2-x}SiO_{5}:Ce_{x}^{3+}$ 형광체 제조와 그 특성)

  • Kim, Sang-Mun;Kang, Kyoung-Tae;Kim, Tae-Ok
    • Journal of the Korean Ceramic Society
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    • v.38 no.9
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    • pp.794-798
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    • 2001
  • $Y_{2-x}SiO_5:Ce_x^{3+}$(x=0.002∼0.04) phosphors were prepared by sol-gel process, amorphous crystal phase was observed in calcining dry gel at 800$^{\circ}$C, but pure $X_2$ type of type $Y_2SiO_5$ phase appeared from heat treatment above 1000$^{\circ}$C. Light absorption of tye $Y_2SiO_5$ host lattice occurred at 230∼360nm, and light absorption of the $Y_{2-x}SiO_5:Ce_x^{3+}$ phosphors was observed at 300∼400nm in adding $Ce^{3+}$. $Y_{2-x}SiO_5:Ce_x^{3+}$ phosphors showed maximum emission shoulder at 436nm. Maximum CL intensities of $Y_{2-x}SiO_5:Ce_x^{3+}$ were observed in adding 0.025 $Ce^{3+}$ and the phosphor showed x=0.161, y=0.124 in color coordinate of CIE1931.

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The Cathodoluminance Properties of $Y_2SiO_5$:Ce Blue Phosphor with Surface Coatings ($Y_2SiO_5$:Ce 청색 형광체의 표면 코팅에 따른 음극선 발광특성)

  • 음현중;김성우;이임렬
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.590-593
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    • 1999
  • $Y_2SiO_5$:Ce was considered as blue phosphor for field emission display because it had an excellent resistance against brightness saturation. But unfortunately It hadn't a sufficient brightness to be applied to FED. In this experiment It-$In_2O_3$, MgO and $SiO_2$ were coated onto $Y_2SiO_5$:Ce phosphor in order to improve the cathodoluminance(CL properties. The coating structures were identified to be the crystalline phases of $In_2O_3$ and MgO respectively. They had fine particle-like shape and were distributed on the surface of $Y_2SiO_5$:Ce phosphor. It was found that the CL efficiency of $Y_2SiO_5$:Ce phosphors were decreased after coatings with In20:j and MgO in voltage range from 500 V to 5 kV. But the brightness of $Y_2SiO_5$:Ce phosphor was increased after coating of 5 0 2 . And also the aging test showed that $In_2O_3$ coating improved the life time of $Y_2SiO_5$:Ce phosphor.

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The Cathodoluminance Properties of ${Y_2}{SiO_5}:Ce$ Blue Phosphor with Surface Coatings (${Y_2}{SiO_5}:Ce$ 청색 형광체의 표면 코팅에 따른 음극선 발광특성)

  • Kim, Seong-U;Lee, Im-Ryeol
    • Korean Journal of Materials Research
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    • v.10 no.8
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    • pp.558-563
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    • 2000
  • $Y_2SiO_5:Ce$ phosphor was coated with $In_2O_3$, $Al_2O_3$ and $SiO_2$ and then their cathodoluminance(CL)proper-ties required in field emission display were investigated. It was found that luminance efficiency and aging p개perty of $Y_2SiO_5:Ce$ phosphor was decreased with $In_2O_3$coating. For the case of coating, the luminance intensity was in blue phosphor was dramatically increased with $SiO_2$ coating. And also the aging property of $Y_2SiO_5:Ce$ Phosphor coated with $SiO_2$ was significantly improved compared to non-coated sample.

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Sol- Gel Synthesis and Luminescent Properties of ${Y_2}{SiO_5}:Ce$ Blue Phosphors (${Y_2}{SiO_5}:Ce$ 청색 형광체의 졸-겔 합성 및 발광특성)

  • Lee, Jun;Han, Cheong-Hwa;Park, Hee-Dong;Yun, Sock-Sung
    • Korean Journal of Materials Research
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    • v.11 no.9
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    • pp.740-744
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    • 2001
  • The $Y_2SiO_5:Ce$ phosphors were synthesized by sol-gel technique in order to improve the performance of blue emitting phosphors for field emission display(FED). The resulted$Y_2SiO_5:Ce$ phosphors enhanced the emission intensity. In addition, calcination temperature of sol-gel technique(1300~140$0^{\circ}C$) was lower than that of the solid state reaction(>1$600^{\circ}C$). Under 365 nm and low voltage electron excitations. $Ce^{3+}$ -activated $Y_2SiO_5$phosphors showed blue emission band with a range of 400~ 430nm. Especially, 2mol% $Ce^{3+}$ doped $Y_2SiO_5:Ce$phosphors showed the maximum emission intensity. We have also controlled drying temperature of wet gel, pH, and $H_2O$/TEOS molar ratio for the optimum condition of TEOS hydrolysis.

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A study on the of Phosphors most suitable a condition of digital FED (디지털전계방출 디스플레이의 형광체 최적조건에 관한 연구)

  • Kim, Soo-Yong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.4
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    • pp.754-759
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    • 2007
  • Field emission displays (FED) are currently being explored as a potential flat panel display technology. Specifically, the optimization pf efficient bin emitting phosphors in the $Y_2O_3-Nb_2O_5$ system and influence of particle size of phosphors on the luminescent properties was studied. Under 254 nm excitation, Bi activated $YNbO_4$ phosphors showed a strong and relatively narrow blue omission band, peaking at about 420-450 nm. Especially 0.4 wt% Bi doped yttrium phosphors showed the maximum emission intensity which is almost three times as much as that of $Y_2SiO_5:Ce$ phosphors. Finally, Ce doped $Y_2SiO_5$ phosphors exhibited strong and broad blue emission band, centered at 390-420 nm and maximum emission intensity at the doping concentration of 0.02-0.03 mol.

Luminescence of $Y_{2-x}Ce_xSiO_5$ Phosphor

  • Han-Soo Kim;Sahn Nahm;Myong-Ho Kim;Kyung-Su Suh;Jae-Dong Byun
    • The Korean Journal of Ceramics
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    • v.3 no.4
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    • pp.245-248
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    • 1997
  • Photoluminescence (PL) and cathodoluminescence (CL) characteristics of Ce-activated $Y_{2-x}Ce_xSiO_5$ have been investigated as functions of Ce concentration and firing condition. According to the X-ray, PL and CL results, $Y_2SiO_5$ is found to have two phases depending on the firing temperature. For the specimen fired above 127$0^{\circ}C$, the emission band peaked at 395nm with a shoulder at 424 nm under ultraviolet (u.v.) and cathode-ray (c.r.) excitation. However, for the specimen fired below 120$0^{\circ}C$ in air the peak was observed at 424 nm and it shifted to longer wavelength with reduction level. The reduced specimen for x=0.02 showed the brightest emission under u.v. excitation whereas under c.r. excitation the brightest emission was observed for the reduced specimen for x=0.06.

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Spherical-shape Y2SiO5:Ce Phosphor Prepared from Organic Precursor Solution by Spray Pyrolysis (고분자 전구체 용액으로부터 분무열분해법에 의해 합성되어진 구형 형상의 Y2SiO5:Ce 형광체)

  • Kang, H.S.;Kang, Y.C.;Park, H.D.;Shul, Y.G.
    • Korean Journal of Materials Research
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    • v.13 no.3
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    • pp.180-184
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    • 2003
  • Ce-doped $Y_2$SiO$_{5}$ phosphor particles of spherical morphology, fine size, high crystallinity and high photoluminescence (PL) intensity were prepared by spray pyrolysis. When nitrate precursor solution is adopted, hollow particles were formed by uneven drying rate between surface and inside of droplet. Citric acid and ethylene glycol were introduced as polymeric precursor to control the morphology of particles. When polymeric solution is adopted, polymeric chain is formed by the esterification reaction between carboxyl and hydroxy groups of citric acid and ethylene glycol, and considered as controlling the drying characteristics of droplet. $Y_2$$SiO_{5}$ :Ce phosphor particles prepared from polymeric precursor solution were spherical, filled, fine size and not agglomerate before and after post heat treatment. The optimum doping concentration of cerium was 0.5 mol% of overall solution concentration. The optimum amount of TBOS of high PL intensity and pure crystallinity of X2-type $Y_2$$SiO _{5}$ was 105% of stoichiometric amount. The PL intensity of $Y_2$X$/_{5}$ :Ce phosphor particles prepared using the polymeric precursor solution was 164% of that of the nitrate precursor solution due to homogeneous composition and good morphology.y.

The Effect of Cerium Reduction on Light Emission in Cerium-containing 20Y2O3-25Al2O3-55SiO2 Glass

  • Maeng, Jee-Hun;Choi, Sung-Churl
    • Journal of the Optical Society of Korea
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    • v.16 no.4
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    • pp.414-417
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    • 2012
  • The effect of cerium concentration and the addition of $Sb_2O_3$ on the light emission of cerium-contained glass were investigated. The glass matrix composition was $20Y_2O_3-25Al_2O_3-55SiO_2$, the $CeO_2$ concentration ranged from 0.05 to 0.5 mol%, and $Sb_2O_3$ was added at concentrations of 0.02 to 0.1 mol%. The $Ce^{3+}$ and $Ce^{4+}$ absorption bands were observed at approximately 330 nm and 240 nm, respectively. A broad emission band at 400 nm, due to the 4f-5d transition of the $Ce^{3+}$ ion, was observed under illumination by a UV light at 330 nm. The photoluminescence intensity of $Ce^{3+}$ had a maximum value at a $CeO_2$ concentration of 0.1 mol%. Adding $Sb_2O_3$ decreased the $Ce^{4+}$ absorption intensity and enhanced the light emission intensity of $Ce^{3+}$ by about 45%.