• 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.

• Korean Journal of Materials Research
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• v.16 no.12
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• pp.761-765
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• 2006

[ $II-III_2-(S,Se)_4$ ] structured of phosphor has been used at various field because those have high luminescent efficiency and broad emission band. Among these phosphors, the europium doped $BaGa_2S_4$ was prepared by solid-state method and had high potential application due to an emissive property of UV region. Also, the common sulfide phosphors were synthesized by using injurious $H_2S\;or\;CS_2$ gas. However, in this study $BaGa_2S_4:Eu^{2+}$ phosphor in addition to excess sulfur was prepared under at 5% $H_2/95%\;N_2$ reduction atmosphere. Thus, this process could be considered as large scale synthesis because of non-harmfulness and simplification. The photoluminescence efficiency of the prepared $BaGa_2S_4:Eu^{2+}$ phosphor increased 20% than that of commercial $SrGa_2S_4:Eu^{2+}$ phosphor. The prepared $BaGa_2S_4:Eu^{2+}$ could be applied to green phosphor for white LED of three wavelengths.

• Journal of the Korean Chemical Society
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• v.50 no.3
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• pp.237-242
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• 2006

Nowadays, LEDs has been applied to the luminescent devices of various fields because of the invention of high efficient blue chip. Recently, especially, the white LEDs composed of InGaN blue chips and a yellow phosphor (YAG:Ce3+) have been investigated extensively. With the exception of YAG:Ce3+ phosphor, however, there are no reports on yellow phosphor that has significant emission in the 450~470 nm excitation range and this LED system is the rather low color rendering index due to their using two wavelength. Hence, we have attempted to synthesize thiogallate phosphors that efficiently under the long wavelength excitation range in the present case. Among those phosphors, we have synthesized Sr2Ga2S5:Eu2+ phosphor by change the host material of SrGa2S4:Eu2+ which is well known phosphor and we investigated the luminescent properties. In order to obtain the harmlessness and simplification of the synthesis process, sulfide materials and mixture gas of 5 % H2/95 % N2 were used instead of the CS2 or H2S gas. The prepared phosphor shows the yellow color peaking at the 550 nm wavelength and it possible to emit efficiently under the broad excitation band in the range of 300~500 nm. And this phosphor shows high luminescent intensity more than 110 % in comparison with commercial YAG:Ce3+ phosphor and it can be applied for UV LED due to excitation property in UV region.

• Korean Chemical Engineering Research
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• v.46 no.3
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• pp.506-511
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• 2008

In this study sol-gel and combustion process was surveyed for the preparation of the red $Y_2O_3$: Eu phosphor, and the properties of phosphor was considered. Chelation and hydrolysis in amorphous citrate sol-gel process were completed in initial reaction stage, and water-forming condensation was superior to organic acid-forming condensation. The mole ratio of citric acid to metal ion had to be above to for the progress of sol-gel process. The dried gel powders are mostly amorphous, and crystallize completely at $700^{\circ}C$, and the crystallinity increases with increasing calcining temperature. The luminescence property of the phosphor was analyzed by measuring the emission spectra. The luminescence intensity increases when the calcination temperature and concentration of metal ions in solution increase.

• Journal of the Korean Chemical Society
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• v.46 no.2
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• pp.164-168
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• 2002

SrGa$_2$S$_4$ : Eu is a green emitting phosphor which is applied for field emission display, and cathodoluminescence. Conventionally, SrGa$_2$S$_4$ : Eu is synthesized by solid state reaction, in which a mixture of SrCO$_3$, Ga$_2$O$_3$, and Eu$_2$O$_3$ is fired at high temperatures under flowing H$_2$S and Ar gases. In this study,SrGa$_2$S$_4$ : Eu phosphor is synthesized by using a decomposition method, where SrS, Eu complex, and Ga com-plex are used. The advantage of this method is that toxic H$_2$S gas and Ar gas are not used. The synthetic con-ditions and luminescent properties of SrGa$_2$S$_4$ : Eu phosphor are also investigated.

• Journal of the Semiconductor & Display Technology
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• v.21 no.4
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• pp.106-109
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• 2022

The green-emitting Zn₂SiO₄:Mn²⁺ phosphor film was evaluated in a xenon excimer lamp. The phosphor film with 2 ㎛ thick was formed of monolithic structure on the inner side of quartz through a long-time annealing process of coated ZnO solution doped with Mn²⁺ ion and SiO₂ of quartz tube. The coated quartz was filled with 100 torr of xenon gas, and simultaneously both sides was melt and sealed. The xenon-field quartz tube was discharge by applying the voltage of 15 kV with a frequency of 26 kHz, and emitted the glow with dominant peak at 172 nm. The vacuum ultraviolet excited the inner-side coated Zn₂SiO₄:Mn²⁺ phosphor film, which emitted the pure and strong green light.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2004.04a
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• pp.44-44
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• 2004

• Proceedings of the Materials Research Society of Korea Conference
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• 1999.05a
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• pp.50-50
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• 1999

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.303-307
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• 2000

The crystal structure of ZnS fabricated by gas-liquid phase reaction was obtained by XRD and refined by RIETAN near R$_{wp}$ factor 10%. The increasement of HCP phase depended on extra H$_2$S gas and the lattice parameter and crystalline size changed by the relative ratio of multiphase. Using ZnS of the different multiphase ratio and crystalline size, sintered ZnS:Cu, Al green phosphor and the CL property resulted optimum luminescence in the range of 91~94% and 150~190$\AA$, respectably, FCC/HCP ratio and crystalline size. As changing of structure ratio, the reason of different luminescence property is now studying. As well as, after XRD pattern of TiO$_2$powder fitted by RIETAN and the structure factor using MEED method simulated about each atom of (002) plane. Additionally, we proposed RIETAN and MEED were the methods of the study of luminescence mechanism for many phosphor materials.s.

• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.150-156
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• 2009

Plasma Display Panels(PDPs) require to have improved luminous efficiency, low manufacturing cost, and high image quality to compete with other flat display devices such as Liquid Crystal Displays(LCDs) and organic light-emitting diodes(OLEDs). In addition, the diversity of product line-up may be needed for high market share. In this paper, the optical characteristics of typical green phosphor for PDP application are reviewed and the problem-based solution will be proposed. We also shortly describe the principle of 3D-PDPs which are promising. Then, the requirement of green phosphor for 3D-PDP application is summarized and research achievement, as of now, is described. The typical problems of $Zn_2SiO_4:Mn$ phosphor, which is the most well-known, are the negatively charged surface property and the long decay time, which leads to unstable discharge in green cell and afterimage. These problems were solved by coating the phosphor surface with metallic oxide. It was found that $Al_2O_3$ would be the best material for $Zn_2SiO_4:Mn$ phosphor. It gives longevity as well as low operating voltage due to the charging effect in green cells. Also, new phosphors, $(Y,\;Gd)Al_3(BO_3)_4:Tb$ and $(Mg,\;Zn)Al_2O_4:Mn$ phosphor are proposed for increasing the luminance and reducing the decay time, which are capable to apply for 3D-PDP application.