• 제목/요약/키워드: green phosphor

검색결과 241건 처리시간 0.03초

증착조건 및 열처리 분위기가 CaWO4 형광체의 발광특성에 미치는 영향 (Effect of Deposition Parameters and Post-annealing on the Luminescent Properties of CaWO4 Phosphor)

  • 한상혁;정승묵;송국현;김영진
    • 한국세라믹학회지
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    • 제40권10호
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    • pp.949-953
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    • 2003
  • 청색 발광특성을 갖는 CaWO$_4$ 형광체를 rf 마그네트론 스퍼터링 방법으로 박막화를 시도하고,증착변수와 열처리 조건이 발광특성에 미치는 영향을 관찰하였다. 증착조건인 산소/아르곤 가스비, 기판온도에 따라서 박막의 구조적, 화학양론적 물성이 크게 영향을 받고 있었다. 후 열처리 공정에 의하여 발광특성의 향상을 얻을 수 있었다. 산소공공에 의한 청록색 영역의 발광도 관찰되었으며, 박막내의 산소결함이 제어되면서 청색 발광스펙트럼을 얻을 수 있었다.

Effect of $Mg^{2+}$ co-doping on luminescent properties of $ZnGa_2O_4:Mn^{2+}$

  • Singh, Binod Kumar;Bartwal, Kunwar Singh;Ryu, Ho-Jin
    • 반도체디스플레이기술학회지
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    • 제6권4호
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    • pp.29-32
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    • 2007
  • Zinc gallate, $ZnGa_2O_4:Mn^{2+}$ co-doped with different concentrations of $Mg^{2+}$ (0.001- 0.5 mol%) was prepared by solid state synthesis method. These compositions were investigated for their photoluminescence and cathodoluminescence properties. The optimized composition $Zn_{0.990}Mg_{0.005}Ga_2O_4:Mn_{0.005}$ shows higher luminescence intensity compared to the parent phosphor. The intense green emission peak was found at 504 nm. The $Mg^{2+}$ doping does not affect much the decay time. It remains <10 ms for these compositions which make them potential candidate for application in TV screens.

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인광물질 인 Ir(PPy)$_3$를 이용한 유기전기발광소자의 효율 개선에 관한 연구 (A Study on the improvement in efficiencies of Organic-Light Emitting Devices Using the Phosphor, Ir(PPy)$_3$)

  • 김준호;김윤명;구자룡;이한성;하윤경
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 하계학술대회 논문집
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    • pp.178-181
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    • 2001
  • The organic light-emitting devices (OLEDs) based on fluorescence have low efficiencies due to the requirement of spin-symmetry conservation. By using the phosphorescent material, the internal quantum efficiency can reach 100 %, compared to 25 % in the case of the fluorescent material. Thus, the phosphorescent OLEDs have recently been extensively studied and showed higher internal quantum efficiencies then the conventional OLEDs. In this study, we investigated the characteristics of the phosphorescent OLEDs, with the green emitting phosphor, Ir(ppy)$_3$ (tris(2-phenylpyridine)iridium). The devices with a structure of ITO/TPD/Ir(PPy)$_3$ doped in the host material/BCP/Alq$_3$/Li:Al/Al were fabricated, and its electrical and optical characteristics were studied. By changing the doping concentration of Ir(PPy)$_3$ and the host materials, we fabricated several devices and investigated the device characteristics.

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열처리조건과 기판이 $ZnGa_O_4:Mn$ 박막 형광체의 발광특성에 미치는 영향 (Effects of heat treatment and substrates on luminescent characteristics of $ZnGa_O_4:Mn$ thin film phosphor)

  • 정승묵;김영진
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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    • pp.181-184
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    • 2004
  • The green emitting phosphor, $ZnGa_2O_4:Mn$ thin film with spinel structure were deposited by rf magnetron sputtering. Thin film phosphors were heat-treated in nitrogen, vacuum and air atmosphere, respectively. The effects of the substrates, heat-treatment conditions and the sputtering parameters were investigated. The growing behavior and luminescent properties of thin films depend on the crystallinity of the substrates. The Ga/Zn atomic ratios and luminescent characteristics were dependent on the annealing conditions.

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Synthesis of an oxynitride-based green phosphor $Ba_3Si_6O_{12}N_2:Eu^{2+}$ via an aqueous-solution process, using propylene-glycol-modified silane

  • Yasushita, Chihiro;Kato, Hideki;Kakihana, Masato
    • Journal of Information Display
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    • 제13권3호
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    • pp.107-111
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    • 2012
  • An almost pure phase of $Ba_3Si_6O_{12}N_2$ doped with $Eu^{2+}$ was successfully synthesized through the ammonia nitridation of an oxide precursor prepared through an aqueous-solution method, using propylene- glycol-modified silane. The emission peak intensity of the obtained $Ba_3Si_6O_{12}N_2:Eu^{2+}$ was -2.2 times higher than that of the sample prepared through a solid-state reaction method.

Low-voltage cathodoluminescent Characteristics of ZnGa$_2$O$_4$ : Mn phosphors

  • 조성희;유재수;이종덕;이중환
    • 한국표면공학회지
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    • 제30권1호
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    • pp.57-62
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    • 1997
  • Green-emitting $ZnGa_2O_4$ : Mn phosphors were synthesized by a thermal method and their low-voltage cathodoluminescent characteristics were examined for the field emitter display (FED) application. Low efficiency of $ZnGa_2O_4$ : Mn phosphors could be ascribed to the low penetration depth of into phosphors, which might results in charge accumulation on the phosphors screen. For increasing cathodoluminescent of $ZnGa_2O_4$ : Mn under low voltage excitation, wide band-gap oxide materials were added to the $ZnGa_2O_4$: Mn powder. It is found that the luminance can be increased by 20%. Measurement of leakage current on the phosphor screen shows that the enhancement of low-voltage cathodoluminescent by additive materials is mainly due to the consumption of surface charges on the phosphor.

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SiO2/ZnS:Cu/ZnS Triplex Layer Coatings for Phosphorescence Enhancement

  • Zhang, Wen-Tao;Lee, Hong-Ro
    • 한국표면공학회지
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    • 제41권4호
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    • pp.169-173
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    • 2008
  • The objective of this study is to coat the $SiO_2$ layer uniformly on the ZnS:Cu phosphors by using Sol-Gel method. From results of SEM micrographs observation, XRD and XPS analysis, it could be confirmed that $SiO_2$ layer was relatively well coated on ZnS:Cu particles. $Ag_2S$ was used as a decoding chemical to analyze the dense and uniform coating performance of $SiO_2$ layer on phosphor particles. It could be concluded that phosphors synthesized from our two step replacement method showed strong blue peak comparing to other method and rather weak green peak also. Obtained particle size of phosphors were about 20m diameter. Luminescence properties of the phosphors were examined by photoluminescence spectra at the excitation wavelength of 270 nm.

Transparent Plasma Display using Transparent Glass Barrier Ribs

  • Lee, Sung-Min;Kim, Seung-Hun;Oh, Seung-Hwa;Shin, Bhum-Jae;Choi, Kyung-Cheol
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.339-341
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    • 2009
  • A transparent plasma display was developed using transparent glass barrier ribs. Glass barrier ribs were fabricated via a wet etching process. Glass barrier ribs created using a top and bottom etching process showed better transparency compared to those created through only a top etching process. A see-through phosphor layer was obtained by coating the sidewall of the barrier ribs with a conventional opaque phosphor. A fabricated prototype of a transparent plasma display was clear enough to see the background beyond the panel and was well operated by a conventional driving scheme. The maximum luminance was 1150 cd/$m^2$ and the maximum luminous efficacy was 1.35 lm/W in a Ne+13.5%Xe gas-mixture and green cells.

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Synthesis of $Ba_2SiS_4:Eu^{2+}$ Blue-Green Phosphor Prepared by Spray Drying Method Using Water Soluble Silicon Compound

  • Tezuka, Satoko;Suzuki, Yoshihito;Petrykin, Valery;Kakihana, Masato
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.243-245
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    • 2009
  • The single phase $Ba_2SiS_4$ doped with $Eu^{2+}$ was successfully synthesized by direct sulfurization of an oxide precursor prepared by a spray drying method using a novel water soluble silicon compound, which remains soluble in a given aqueous solution. The intensity of the emission peak of thus obtained $Ba_2SiS_4:Eu^{2+}$ was 1.75 times larger than that of a sample prepared by a solid state reaction method, and it approached 106% compared to one of the best commercially available YAG:$Ce^{3+}$ phosphor.

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Inorganic phosphors for LED applications

  • Winkler, Holger;Barnekow, Peter;Benker, Andreas;Petry, Ralf;Tews, Stefan;Vosgroene, Tim
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.56-59
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    • 2009
  • In the nineties the invention of the InGaN blue LED has innovated illumination technology. Currently LCD backlighting and more and more general lighting applications are based on white LEDs comprising of inorganic phosphors and blue emitting InGaN chip. Well established phosphor materials are ortho silicates and garnets like yellow emitting YAG:Ce. In our paper we demonstrate that garnet materials also allow for green light emission for both, general lighting and backlighting LED applications.

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