• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.594-597
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• 1999

The new green and red phosphors for PDP application activated by T $b^{3+}$ and E $u^{3+}$ were synthesized, and their photoluminance properties were investigated. It was found that the brightness of $Al_3$Gd $B_4$ $O_{12}$ :T $b^{3+}$ green phosphor under 147nm VUV irradiation was higher than that of commercial Z $n_2$ $SiO_4$:M $n^{2+}$ phosphor. But the emitting intensity of A1$_3$Gd $B_4$ $O^{12}$ :E $u^{3+}$ red phosphor was inferior to the commercial (Y,Gd)B $O_3$:E $u^{3+}$. $Al_3$Gd $B_4$ $O_{12}$ Phosphor had a strong excitation band at 160nm associated with the host absorption, and also the photoluminance excitation intensity of $Al_3$Gd $B_4$ $O_{12}$ :T $b^{3+}$ was higher than that of Z $n_2$ $SiO_4$:M $n^{2+}$, but the intensity of $Al_3$Gd $B_4$ $O_{12}$ :E $u^{3+}$ phosphor was smaller than (Y,Gd)B $O_3$:E $u^{3+}$ phosphor In the VUV range. C $e^{3+}$ co-doping in A1$_3$Gd $B_4$ $O^{12}$ :E $u^{3+}$ and substitution of $Al^{3+}$ by G $a^{3+}$ A1$_3$Gd $B_4$ $O^{12}$ :E $u^{3+}$ phosphor were tried, but they did not improved the optical property .d the optical property .ty .

• Journal of Powder Materials
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• v.24 no.6
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• pp.457-463
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• 2017

Nanosized $Gd_2O_3:Eu^{3+}$ red phosphor is prepared using a template method from metal salt impregnated into a crystalline cellulose and is dispersed using a bead mill wet process. The driving force of the surface coating between $Gd_2O_3:Eu^{3+}$ and mica is induced by the Coulomb force. The red phosphor nanosol is effectively coated on mica flakes by the electrostatic interaction between positively charged $Gd_2O_3:Eu^{3+}$ and negatively charged mica above pH 6. To prepare $Gd_2O_3:Eu^{3+}$-coated mica ($Gd_2O_3:Eu/mica$), the coating conditions are optimized, including the stirring temperature, pH, calcination temperature, and coating amount (wt%) of $Gd_2O_3:Eu^{3+}$. In spite of the low luminescence of the $Gd_2O_3:Eu/mica$, the luminescent property is recovered after calcination above $600^{\circ}C$ and is enhanced by increasing the $Gd_2O_3:Eu^{3+}$ coating amount. The $Gd_2O_3:Eu/mica$ is characterized using X-ray diffraction, field emission scanning electron microscopy, zeta potential measurements, and fluorescence spectrometer analysis.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.3
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• pp.258-263
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• 2002

We present a new toed phosphor, $Gd_{2-x-y}Li_xEu_yO_3$ with superior luminescent Properties compared to the commercially available red phosphor $Y_2O_3:Eu^{3+}$. The phosphor, with a diameter of about $2\mu\textrm{m}$, consists of the psedospherical particles in a regular array. The photoluminescence measurements as a function of the laser power and the Eu mole fraction were performed at zoom temperature The luminescence intensity linearly increases as both the laser power and the Eu mole fraction Increase. As for the dependence on cathodoluminescence, the incorporation of Eu and Li ions into $Gd_2O_3$ lattice brings about an increase in luminescent efficiency. The highest emission intensity for the phosphor occurs at the applied voltage of 500 V, its value is larger than that of $Y_2O_3:Eu^{3+}$ powder by 70%.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1355-1359
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• 2006

Due to its efficient red emission, $Eu^{3+}$ ion has been doped in various host materials. $GdCa_4B_3O_{10}:Eu^{3+}$ phosphor for red emission has been prepared by solid state reaction. Photoluminescence properties for the phosphor under UV and VUV excitation were investigated. The $GdCa_4B_3O_{10}:Eu^{3+}$ phosphor under both excitation conditions shows typical red emission spectrum centered at 611 nm with several weak peaks due to energy transfer from $^5D_O\;to\;^7F_J(J=1,2,3,4)$ of $Eu^{3+}$ ion. On the other hand, the activator content exhibiting the concentration quenching under UV and VUV irradiation is 10 mole% and 2.5 mole%, respectively.

• 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.

• Korean Journal of Materials Research
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• v.10 no.1
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• pp.49-54
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• 2000

The new green $Al_3GdB_4O_{12}:Tb^{3+} and red Al_3GdB_4O_{12}:Eu_{3+}$ phosphors were synthesized and then characterized their optical properties for PDP application. And also the photoluminescence properties of these phosphors were compared with the commercial green $Zn_2SiO_4:Mn^{2+} and (Y,Gd)BO_3: Eu^{3+}$ red PDP phosphors. The phosphors were synthesized by solid state reaction at 115$0^{\circ}C$ for 4hr. It was found that the emitting brightness of $Al_3GdB_4O_{12}:Tb^{3+}$(15mol%) green phosphor under 147nm excitation was higher than that of commercial $Zn_2SiO_4: Mn^{2+}$ green PDP phosphor. However, the color coordinate of this new green phosphor was inferior to the commercial one. On the other hand, the emitting intensity of $Al_3GdB_4O_{12}:Eu^{3+}$(15mol%) red phosphor was smaller than the $commercial(Y,Gd)BO_3: Eu^{3+}$ red one, but the CIE coordinate was slightly improved. The excitation spectrum showed that $Al_3GdB_4O_{12}$ phosphors had a strong excitation band at $\lambda=160nm$ associated with the host absorption. And the photoluminance excitation (PLE) intensity in VUV range for $Al_3GdB_4O_{12}:Tb^{3+}$ green phosphor was higher than that of $Zn_2SiO_4: Mn^{2+}$, but the PLE intensity of $Al_3GdB_4O_{12}:Eu^{3+}$ red phosphor was smaller than $(Y,Gd)BO_3: Eu^{3+}$.

• Korean Journal of Materials Research
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• v.27 no.10
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• pp.534-543
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• 2017

$Gd_2O_3:Eu^{3+}$ red phosphors were prepared by template method from crystalline cellulose impregnated by metal salt. The crystallite size and photoluminescence(PL) property of $Gd_2O_3:Eu^{3+}$ red phosphors were controlled by varying the calcination temperature and $Eu^{3+}$ mol ratio. The nano dispersion of $Gd_2O_3:Eu^{3+}$ was also conducted with a bead mill wet process. Dependent on the time of bead milling, $Gd_2O_3:Eu^{3+}$ nanosol of around 100 nm (median particle size : $D_{50}$) was produced. As the bead milling process proceeded, the luminescent efficiency decreased due to the low crystallinity of the $Gd_2O_3:Eu^{3+}$ nanoparticles. In spite of the low PL property of $Gd_2O_3:Eu^{3+}$ nanosol, it was observed that the photoluminescent property was recovered after re-calcination. In addition, in the dispersed nanosol treated at $85^{\circ}C$, a self assembly phenomenon between particles appeared, and the particles changed from spherical to rod-shaped. These results indicate that particle growth occurs due to mutual assembly of $Gd(OH)_3$ particles, which is the hydration of $Gd_2O_3$ particles, in aqueous solvent at $85^{\circ}C$.

• Transactions on Electrical and Electronic Materials
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• v.9 no.2
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• pp.57-61
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• 2008

The $(Y,Gd)_2O_3$:Eu phosphors were synthesized using the impregnation method in order to improve the performance of red-emitting phosphors for plasma display panels. $(Y,Gd)_2O_3$:Eu phosphors, with a particle size ranging from 150 and 200 nm, exhibited a strong red emission at around 615 nm. The emission intensity and particle size of the powders were controlled by adjusting the sintering temperature and raw material composition. The resulting particle size was very uniform and photoluminescence (PL) characteristic was excellent, being about twice that of commercial red phosphor.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.04a
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• pp.151-154
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• 2003

The synthesis and luminescent properties of trivalent europium activated gadolinium oxide red phosphors by sol-gel process have been investigated. Aqueous metal nitrate solution was mixed with EDTA which was chosen by the most suitable material of sol-gel formation as chelating agents. We noticed that the samples when are heated with EDTA at a temperature of $100^{\circ}C$ for lhrs, produced brownish and crisp powders due to condensation reaction on decomposition, dehydration and formation of sol-gel. Hence, when the powder pre-heated at about $100^{\circ}C$ was then heated at $1200^{\circ}C$ for 3hrs in atmosphere, the luminescence properties of resultant $Gd_{2}O_{3}:Eu^{3+}$ phosphor was measured by SEM, FT-IT and brightness intensity was shown 20% higher than those prepared by conventional method and by other chelating agent.

• Journal of the Korean Chemical Society
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• v.46 no.4
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• pp.336-345
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• 2002

In this study, we have screened $Eu^{3+}$- and $Tb^{3+}$-activated candidate phosphors for PDP in the sys-tems of CaO-Gd$_2$O$_3$-Al$_2$O$_3$ by combinatorial chemistry and investigated the synthetic temperature, optimum com-position and luminescent properties about the candidate phosphors. To construct the emission intensity library by VUV PL, we have synthesized 210 different compositional samples using a polymerized-complex method. Good luminescent samples were identified by X-ray diffraction method. $Ca_$\alpha$$G$d_{0.95-$\alpha$-$\beta$}Al_$\beta$O_$\delta$$ : Eu(0.02< $\alpha$+$\beta$ <0.04) phos-phors screened as a red phosphor have good color purity than commercial phosphor. In the candidate phosphors of CaGdAl$_3O_7$ : Tb, Ca$Al_{12}O_{19}$ : Tb, Gd$_4$Al$_2O_9$ : Tb, and Gd$_3Al_5O_{12}$ : Tb CaGdAl$_3O_7$ : Tb, and Ca$Al_{12}O_{19}$ : Tb have shorter decay time than commercial phosphor.