• 한국세라믹학회지
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• 제43권11호
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• pp.743-745
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• 2006

The luminescence properties of $Sr_{1-x}Ba_xTiO_3:Pr$, Al red phosphor for Field Emission Displays (FEDs) have been investigated in powders prepared though solid-state reactions. $Sr_{1-x}Ba_xTiO_3:Pr$, Al red phosphors indicate a higher luminescent intensity, and have been found to have potential for field emission displays. The addition of Ba increased the luminescence intensity at 617 nm by up to 30%. Ba ions are effective in producing the energy transfers from host-to-activator in 4f-5d transitions.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권2호
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• pp.62-66
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• 2004

This paper investigated the characteristics of a newly developed high density hollow cathode plasma (HCP) system and its application for the etching of silicon wafers. We used SF$_{6}$ and $O_2$ gases in the HCP dry etch process. Silicon etch rate of $0.5\mu\textrm{m}$/min was achieved with $SF_6$$O_2$plasma conditions having a total gas pressure of 50mTorr, and RF power of 100 W. This paper presents surface etching characteristics on a crystalline silicon wafer and large area cast type multicrystlline silicon wafer. The results of this experiment can be used for various display systems such as thin film growth and etching for TFT-LCDs, emitter tip formations for FEDs, and bright plasma discharge for PDP applications.s.

• Journal of Korean Vacuum Science & Technology
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• 제3권1호
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• pp.90-94
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• 1999

Field Emission display (FEDs) require enhancement in both driving methods and process techniques to improve the display image quality. However, from the point of view of manufacturing, it is difficult to find methods and techniques to realize low cost manufacturing. New and simple color phosphor screen designs were suggested with non-crossed electrode lines and full color anode panels for small area displays were demonstrated. To avoid unwanted reaction with gases produced from phosphors in a high vacuum glass container, a very thin polyimide layer was coated on the phosphor screen. Moreover, to improve the display image quality, black matrix composed of inorganic materials was fabricated. This paper describes the performance and characteristics of the new full color anode panels.

• 대한방사선기술학회지:방사선기술과학
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• 제31권3호
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• pp.287-292
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• 2008

방사선 반응에서의 위치정보는 방사선 선원의 영상을 재구성하는데 있어서 매우 중요한 기본정보이다. 이에 대부분의 위치 검출 기술을 이용하여 검출기안에서의 일어난 단일 반응의 위치정보를 알아낼 수 있다. 그러나 섬광체 안에서의 다중산란의 경우 각각의 산란위치를 개별적으로 측정할 수 없고 여러 산란위치의 평균만이 구해질 수 있어서 측정된 방사능의 위치정보에 불확실성이 존재하게 된다. 이 논문에서는 이러한 다중산란에 따른 위치 불확실성을 몬테카를로 시뮬레이션으로 계산하였다. 시뮬레이션 모델은 복합 집속 카메라에 사용된 $50{\times}50{\times}5mm\;LaCl_3$(Ce) 섬광체(pixel크기는 $2{\times}2{\times}5mm$)이다. 복합 집속 카메라는 광전효과와 컴프턴 산란 모두에서 정보를 얻으므로 방사선의 반응에서 부분에너지만 (검출기에) 검출되는 경우와 모든 에너지가 검출 되는 경우를 나누어 위치 불확실성을 계산하였다. 부분에너지만 검출되는 경우 (PED) 위치의 표준편차는 $1{\sim}2mm$ 미만으로 다중산란에 의한 불확실성이 크지 않다는 것을 알 수 있다. PED의 경우 다중산란의 영향이 크지 않으므로 이러한 다중산란은 컴프턴 카메라의 성능에 큰 영향을 미치지 않는다는 것을 알 수 있다. 그러나 모든 에너지가 검출되는 경우 (FED), 122keV입사방사선의 경우를 제외하면, 그 위치의 표준편차가 1차 검출기의 pixel크기에 2배에 달한다. 그러므로 복합 집속 카메라의 코드화된 마스크를 설계하는데 있어 재구성된 영상의 잡음을 방지하기 위해 다중산란에 의한 표준편차가 고려되어야 한다. 모든 입사 방사선에너지에 대하여 FED에 의한 위치 불확실성은 PED에 의한 것 보다 크며 PED 대 FED의 비는 입사방사선의 에너지가 증가함에 따라서 커진다. PED와 FED의 경우 모두 위치의 불확실성이 입사방사선의 에너지에 따라 달라졌다.

• Journal of Information Display
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• 제7권2호
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• pp.16-21
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• 2006

The effect of improvement on the surface morphology of screen-printed carbon nanotube (CND) films was studied by using the optically clear poly-dimethylsiloxane (PDMS) elastomer for surface treatment. After the PDMS activation treatment was applied to the diode-type CNT cathode, the entangled carbon nanotube (CNT) bundles were broken up into individual free standing nanotubes to remarkably improve the field-emission characteristics over the as-deposited CNT film. Also, the cathode film morphology of a top gated triode-type structure can be treated by using the proposed surface treatment technique, which is a low-cost process, simple process. The relative uniform emission image showed high brightness with a high anode current. This result shows the possibility of using this technique for surface treatment of large-size field emission displays (FEDs) in the future.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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• pp.1459-1461
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• 2005

Carbon nanotube -copper composite structures were fabricated using composite plating method and their field emission characteristics were investigated. Multi-walled carbon nanotubes synthesized by chemical vapor deposition were used in the present study. It was revealed that turn-on field of the structures was about 3.0 $V/{\mu}m$ at the current density of 0.1 ${\mu}A/cm^2$. We observed relatively uniform emission characteristics as well as stable emission currents. CNT-Cu composite plating method is efficient and it has no intrinsic limit on the plating area. Moreover, it gives strong adhesion between emitters and an electrode. The refore, we expect that CNT-Cu composite plating method can be applied to fabricate electron field emitters for large area FEDs and large area vacuum lighting sources.

• 대한의생명과학회지
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• 제7권1호
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• pp.47-51
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• 2001

To investigate an effect of the topical toluene application to .at skin on the liver injury, toluene (35 mg/$cm^2$) was sequentially applied for 3 or 5 days to rat skin and then the animals were sacrificed. 5 day toluene-treated rats showed the slight increase of live. weight per body weight(%) compared with control. Serum levels of xanthine oxidase and alanine aminotransferase activity were significantly increased both in 3 days and 5 days toluene-treated animals compared with control. In the histopathological findings, cytoplasmic degeneration of hepatocytes around the central vein was noted in the liver of rats applied with toluene to the skin. These results indicate toluene application to rat skin feds to somewhat slight liver injury. On the other hand, the hepatic benzylalcohol or aldehyde dehydrogenase activities were significantly decreased by toluene application to rat skin. In conclusion, the liver min was induced by toluene application to rat skin, and it can be hypothesized that accumulation of benzaldehyde in liver cell may be responsible for liver injury.

• 한국전기전자재료학회논문지
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• 제16권12S호
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• pp.1248-1254
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• 2003

Carbon nanotubes(CNTs) are grown by using Co catalyst metal. CNTs fabricated by PECVD(plasma enhanced chemical vapor deposition) method are studied in terms of surface reaction and surface structure by TEM and Raman analysing method and ate analysed in its electrical field emission characteristics with variation of space between anode and cathode. Acetylene(C$_2$H$_2$) gas is used as the carbon source, while ammonia and hydrogen gas are used as catalyst and dilution gas. The CNTs grown by hydrogen(H$_2$) gas plasma indicates better vortical alignment, lower temperature process, and longer tip, compared to that grown by ammonia(NH$_3$) gas plasma. The CNTs fabricated with Co(cobalt) catalyst metal and PECVD method show the multiwall structure in mid-circle type in tip-end and the inner vacancy of 10nm. Emission properties of CNTs indicate the turn-on field to be 2.6 V/${\mu}{\textrm}{m}$ We suggest that CNTs can be possibly applied to the emitter tip of FEDs and high brightness flat lamp because of low temperature CNTs growth, low turn-on field.

• Bulletin of the Korean Chemical Society
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• 제29권4호
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• pp.822-826
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• 2008

We report the cathodoluminescence and aging properties of a series of green phosphors of formula $Sr_{1-x}M_xGa_2S_4$:Eu (x = 0.0-1.0, M = Ba or Ca) that have potential applications in field emission displays (FEDs). The series of phosphors was synthesized via NaBr-aided solid-state reactions in a flowing $H_2S$ stream. A low level ($\sim$20%) of Ba or Ca substitution for Sr in $SrGa_2S_4$:Eu maintains the orthorhombic phase of pure $SrGa_2S_4$:Eu phosphors. Further, a low level ($\sim$20%) of Ba or Ca substitution for Sr in $SrGa_2S_4$:Eu provides various green colors and sufficient brightness for FED applications. Substitution of Ba or Ca for Sr in $SrGa_2S_4$:Eu also improved the stability of the phosphor when it was operated under electron-beam irradiation of 5 kV.

• Journal of Information Display
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• 제2권4호
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• pp.1-7
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• 2001

This paper investigates the characteristics of a newly developed high density hollow cathode plasma(HCP) system and its application for the etching of silicon wafers. We used $SF_6$ and $O_2$ gases in the HCP dry etch process. This paper demonstrates very high plasma density of $2{\times}10^{12}cm^{-3}$ at a discharge current of 20 rna, Silicon etch rate of 1.3 ${\mu}m$/min was achieved with $SF_6/O_2$ plasma conditions of total gas pressure of 50 mTorr, gas flow rate of 40 seem, and RF power of200W. This paper presents surface etching characteristics on a crystalline silicon wafer and large area cast type multicrystlline silicon wafer. We obtained field emitter tips size of less than 0.1 ${\mu}m$ without any photomask step as well as with a conventional photolithography. Our experimental results can be applied to various display systems such as thin film growth and etching for TFT-LCDs, emitter tip formations for FEDs, and bright plasma discharge for PDP applications. In this research, we studied silicon etching properties by using the hollow cathode plasma system.