• Title/Summary/Keyword: new phosphor

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A Modified Ramp Reset Waveform for High Contrast Ratio in AC PDPs

  • Kim, Jae-Sung;Yang, Jin-Ho;Ha, Chang-Hoon;Whang, Ki-Woong
    • Journal of Information Display
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    • v.3 no.4
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    • pp.13-18
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    • 2002
  • In general, the background light that is produced during the reset period deteriorates the dark room contrast ratio in AC PDP. In this paper, we propose a modified ramp reset pulse that can reduce the background light to an imperceptible level. In the new reset waveform, the discharges between the scan and sustain electrodes are minimized by applying a positive bias voltage to the sustain electrode and only the weak discharges between the scan and address electrodes are found to occur during the reset period. We also adopted the MgO coated phosphor layer to improve the address voltage margin that was reduced when the bias voltage in the modified ramp reset waveform was applied. As a result, the address voltage margin of 45 V which is the same level of the conventional method was ortained and the dark room contrast ratio was improved up to 7500 : 1.

Synthesis and luminescence of silver doped zinc sulfide phosphor

  • Jeong, Young-Ho;Khatkar, S.P.;Park, Jin-Won;Hua, Yang;Han, Sang-Do
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.1013-1016
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    • 2003
  • A new route for the synthesis of silver doped of zinc sulfide phosphor by combustion method has been investigated. Silver nitrate was decomposed with urea or carbohydrazide to give small size particles in presence of alkali metal halides at low temperature compared to the conventional method. The high temperature inherent to the highly exothermic nature of redox reaction leads to well-crystallized powder in short time. The phosphors thus obtained were further heated at $1050^{\circ}C$ in an inert atmosphere for 3hrs to get better luminescence properties.

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Analysis of Enhancement in Phosphor Performance induced by Surface Treatments

  • Jeon, Duk-Young;Bukesov, Sergey A.;Kim, Jin-Young;Park, Zin-Min;Lee, Dong-Chin
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.370-373
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    • 2003
  • A search for a new phosphor composition of excellent performance in systematic ways requires lots of research efforts, and often turns out to be very timeconsuming and difficult. Thus, usually practical ways are taken to improve the performance of phosphors. A few examples of practical surface treatments on phosphors such as $In_2O_3$ coating on $ZnGa_2O_4:Mn$, phosphoric acid treatment on ZnS:Ag,Cl, and base KOH treatment with ultrasonication on ZnS:Ag,Cl are presented. The reasons for the improvement of luminescence intensity or degradation properties after these treatments are discussed based upon careful analyses on the surface of the phosphors and a proposed model on charge carriers generated by electron beam excitation.

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Synthesis and Characterization of High Luminance ${Zn_2}{SiO_4}$:Mn Phosphors (고발광 ${Zn_2}{SiO_4}$:Mn 형광체의 제조 및 특성)

  • 성부용;정하균;박희동;김대수
    • Journal of the Korean Ceramic Society
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    • v.37 no.8
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    • pp.774-780
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    • 2000
  • In order to improve luminescence prperty of phosphors, we have synthesized Zn2SiO4:Mn phosphors by a new chemical synthetic route, i.e., the homogeneous precipitation method. This method has featured that the formation of phosphoris completed at relatively low temperature of 105$0^{\circ}C$ and the particle morphology exhibits spherical shape to be well-dispersed and uniform size. At all the Mn concentration explored, phosphors prepared by this method have exhibited the improved emission intensities. In particular, the emission intensities of phosphors with Mn doping contents between 1 at% and 3.5 at% were higher about 40% than that of commercial phosphor. On the other hand, the decay time has been decreased from 23 ms to 11 ms with increasing Mn concentration. In addition, the phosphor composition containing 3 at% Mn has displayed the most saturated color.

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High brightness property of Power Electroluminescent Device using ZnS:Cu (ZnS:Cu를 이용한 후막 전계발광소자의 고휘도 특성)

  • Lee, Jong-Chan;Park, Dae-Hui
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.48 no.5
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    • pp.349-353
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    • 1999
  • In this paper, to fabricate the AC power electroluminescent device (PELD) with high brightness, new structure that constructed single emissive layer between electrodes was proposed. Dielectric and phosphor material structure that constructed single emissive layer between electrodes was proposed. Dielectric and phosphor material were BaTiO3 and ZnS:Cu respectively. Fabricated AC power EL devices were estimated by optical and electrical properties of EL spectrum, brightness, CIE coordinate system, transferred charge density and EL emission wave in time domain. With above results, we found that brightness of newly proposed AC powder EL power EL device was 2754 cd/m2 at 100V, 400 Hz and compared with conventional device structure.

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Recent progress in oxide phosphor thin-film electroluminescent devices

  • Minami, Tadatsugu;Miyata, Toshihiro
    • 한국정보디스플레이학회:학술대회논문집
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    • 2006.08a
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    • pp.27-32
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    • 2006
  • The present status and prospects for further development of thin-film electroluminescent (TFEL) devices using oxide phosphors are described. High-luminance oxide TFEL devices have been recently developed using a new combinatorial deposition technique featuring rf magnetron sputtering with a subdivided powder target. In addition, new flexible oxide TFEL devices have been fabricated on an oxide ceramic sheet and operated stably in air above $200^{\circ}C$.

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New Ramp-reset Waveform for Fast Addressing in AC-PDPs

  • Kim, Oe-Dong;Ahn, Byoung-Nam;Choi, Kwang-Yeol;Yoo, Eun-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.643-646
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    • 2005
  • We present new ramp-reset waveforms that realize fast addressing in AC-PDPs. These waveforms distort the distribution of wall charges on the surface of a phosphor layer: hence, the enhanced electric field helps to ignite a cell faster. They also reduce the black luminance: the divide of erasing ramp down discharges into two parts, i.e. a surface discharge and a vertical discharge, makes lower luminance.

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Search for Phosphors for Use in Displays and Lightings using Heuristics-based Combinatorial Materials Science

  • Sharma, Asish Kumar;Sohn, Kee-Sun
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.207-210
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    • 2009
  • According to the recent demand for materials for use in various displays and solid state lightings, new phosphors with improved performance have been pursued consistently. Multi objective genetic algorithm assisted combinatorial material search (MOGACMS) strategies have been applied to various multi-compositional inorganic systems to search for new phosphors and to optimize the properties of phosphors.

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