• 제목/요약/키워드: phosphor

검색결과 1,149건 처리시간 0.035초

Gaseous Changes during Discharge ant Thermal Treatment in Plasma Display Panel (PDP)

  • Hwang, Ji-Hee;Yang, Seung-Jean;Jun, Moon-Gue;Kim, Young-Chai
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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    • pp.1199-1202
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    • 2005
  • Inside of working PDP, there exist highly reactive conditions in the gap between two glass panels. MgO film and phosphor have been investigated as a function of discharge, also phosphor and sealing frits have been investigated as a function of temperature. Changes of impurity generation of MgO, phosphor and sealing fits were measured by using x-ray photoelectron spectroscopy (XPS) and quadropole mass spectroscopy (XPS) and quadropole mass spectrometer (QMS). Impurities such as CO, $CO_2$, OH and $H_2O$ were increased during discharge and heating treatment. Gaseous impurities such as carbon compounds and water deteriorated the characteristics of PDP operation during of lifetime. So metal is used to remove the impurities of phosphor and sealing frits during hearting, the result that the quantity of the impurities such as carbon monoxide and water was reduced.

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Photoluminescence and cathodoluminescence properties of Tb-activated calcium zirconate phosphor

  • Lee, Dae-Won;Oh, Jae-Suk;Jung, Ha-Kyun
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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    • pp.1523-1525
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    • 2005
  • $CaZrO_3:Tb$ as a new green-emitting phosphor, has been synthesized by solid state reaction. Photoluminescence and cathodoluminescence properties for the phosphor with a Perovskite structure were investigated. The $CaZrO_3:Tb$ phosphor, which has several emission peaks due to energy transfer from $^5D_4$ to $^7F_J(J=6,5,4,3)$ of $Tb^{3+}$ ion, exhibited strong green luminescence with the main emission peak centered at 545 nm. Optimum Tb concentration was 0.02mol%.

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Luminescence of $Eu^{3+}-doped\;GdCa_4B_3O_{10}$ phosphor under UV and VUV irradiation

  • Oh, Jae-Suk;Kwak, Chung-Heop;Jung, Ha-Kyun
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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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.

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Luminescent properties of magnesium thiogallate phosphor with green emission for LEDs

  • Kim, Kyung-Nam;Kim, Jae-Myung;Choi, Kyoung-Jae;Park, Joung-Kyu;Kim, Chang-Hae
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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    • pp.1331-1333
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    • 2005
  • A magnesium thiogallate phosphor doped with europium was prepared by solid-state method. This phosphor has green emission near 535 nm due to the allowed transition from $4f^65d$ at an excitation state $(T_{2g})$ to $4f^7 (^8S_{7/2}) at a ground state of $Eu^{2+}$ ion. This phosphor shows a wide excitation spectrum from ultra violet (300 nm) to bluish green (515 nm).

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고휘도 후막 전계발광소자에 관한 연구 (A Study on Powder Electroluminecscent Device for High Brightness)

  • 오주열;이종찬;박대희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 D
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    • pp.1382-1384
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    • 1998
  • Electroluminescence is occurred when phosphor is located in electric field. Object of this research show new type of powder electroluminescent device (PELD) for high brightness compared with conventional PELD. New type of PELD structured as follow ITO/phosphor + dielectric/Silver paste). To investigate optical properties of PELDs, EL spectrum, CIE coordinate system, Brightness of PELDs was measured. The suitable ratio between phosphor and dielectric in new type of PELD was 7:3(phosphor:dielectric). At 200 V 400 Hz, new type of PELD which had ratio of 7:3 was 5700 cd/$m^2$.

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Study on the Improvement of Indirect Intra-Oral Dental Digital X-ray Image Sensor with Optical Coupling

  • Whang, Joo-Ho;Chung, Jin-Bum;Kim, Tae-Woo
    • Nuclear Engineering and Technology
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    • 제33권5호
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    • pp.514-525
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    • 2001
  • Optimum characteristics of digital X-ray sensor components were analyzed to develop intra- oral dental digital X-ray image sensor using indirect method. Parametric analysis was carried out to optimize the phosphor thickness and the fiber optic plate (FOP) coupling to charge coupled device (CCD). X-ray absorption and light diffusion in the phosphor layer were analyzed by the Monte Carlo method. Real time X-ray image was obtained with prototype X- ray image sensor using general CCD camera with 1∼10 Ip/mm resolution. It has been previously shown that large resolution degradation in X-ray images was caused by miss alignment of FOP to CCD and optical adhesive selection. In this study, we reported that X-ray image quality was greatly improved by using optimized characteristics of alignment device and phosphor thickness.

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조합화학을 이용한 망간(2+)과 유로피움)2+)이 첨가된 Barium Hexaaluminate 형광체의 합성 및 광특성 분석 (Synthesis of Barium Hexaaluminate Phosphros Using Combinatorial Chemistry)

  • 박응석;최윤영;손기선;김창해;박희동
    • 한국세라믹학회지
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    • 제37권2호
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    • pp.134-139
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    • 2000
  • The main objective of the present investigation is to show the feasibility of combinatorial chemistry by applying this method to phosphor syntehses. In this respect barium hexaaluminate phosphor was prepared by the split-pool combinatorial method, which enabled much more rapid search of optimum compositions of target phosphors than conventional synthetic methods. Barium hexaaluminate phosphors doped with Eu2+ exhibit blue emission while those co-doped with Mn2+ and Eu2+ exhibit green emission. Basically, the phosphor doped with 1.3 mole of Ba and 0.06~0.15 mole of Eu2+ exhibit the maximum value of emission intensity at 435${\mu}{\textrm}{m}$. Under the UV and VUV extitations, the barium hexaaluminate phosphor co-doped with Mn2+ and Eu2+ shows strong green emission.

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무기EL용 형광체 제작 및 구동특성 (Production and Operating Characteristics for Inorganic EL Phosphor)

  • 팍품;이돈규;곽동주;성열문
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2015년도 제46회 하계학술대회
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    • pp.1132-1133
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    • 2015
  • In this paper, we are presents production and operation characteristics for inorganic EL phosphors device using screen printed. The EL device is composed as ITO PET / EL phosphors dielectric $(2{\times}2cm^2)/TiO^2$ paste/Ag electrode. At 100Vac 400Hz, the luminescence of inorganic EL phosphors were $60.33cd/m^2$ of red phosphor, $42.12cd/m^2$ of green phosphor and $58.45cd/m^2$ of blue phosphor. The output current was 12.57 mA, 17.11 mA and 11.98 mA, respectively. The inorganic EL phosphors of EL device are increasing efficiency EL device.

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Control of Blue Phosphor Layer Cross-section and Its Improved Discharge Characteristics

  • Jeon, Byung-Soo;Choi, Seo-Young;Moon, Cheol-Hee;Heo, Eun-Gi;Lee, Kwang-Sik;Whang, Ki-Woong;Bae, Chul-Han
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.583-585
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    • 2002
  • The effects of phosphor properties such as the granular sizes and shape on the crosssectional shape of phosphor layer and plasma discharge characteristics for improving the luminance and luminous efficiency in ac PDP have been investigated. As the granular size decreases, the thickness of vertical side of barrier rib in blue cell decreases, and wheras the thickness of bottom side increases due to increased dispersibility. In addition, the phosphor with round granular shape showing good dispersibility shows better voltage margin and higher luminous efficiency due to their improved discharge volume and packing density.

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Calculation of the Quantum Efficiency of Phosphor Screens in CRTs and FL Tubes

  • Ozawa, Lyuji;Tian, Yakui
    • Journal of Information Display
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    • 제11권3호
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    • pp.128-133
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    • 2010
  • The quantum efficiencies of CRT and FL tubes that use a phosphor screen as transducer of invisible particles to light in visible spectrum wavelengths were calculated in this study. The phosphor screens in CRT tubes have quantum efficiencies greater than 3,000, which give the luminance of comfortable images on phosphor devices for the observation by the eyes. The established FL tubes have the amazing quantum efficiency of $3{\times}10^{10}$ photons per moving electron per FL tube, which allows the illumination of a $5{\times}5\;m^2$ room by three FL tubes, with heating at $40^{\circ}C$. Thus, FL tubes, including for backlighting of LCD displays, have a superior over other illumination sources.