• 제목/요약/키워드: CaS:$Eu^{2+}$

검색결과 44건 처리시간 0.025초

Synthesis of Sulfide-based Phosphors by Multiply Combined Methods Based Upon Inorganic Chemistry

  • Kakihana, Masato;Petrykin, Valery
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.121-124
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    • 2009
  • We developed a panel of innovative solution-based approaches for synthesis of multicomponent sulfide phosphor materials. The application of these synthesis strategies allowed for preparation of high-purity and high-brightness $BaAl_2S_4:Eu$ and $Ba_2SiS_4:Eu$ phosphors and led to the discovery of new phosphors suitable for application in the LED-based lighting including $Sr_2ZnS_3:Eu$, $CaBaSiS_4:Eu$ and $(Ba,Sr)_2ZnS_3:Eu$.

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Tb, Eu, EuTb가 치환된 가네트 단결정 막의 성장과 자기적 특성 (Growth and magnetic properties of Tb, Eu, EuTb-substituted garnet single crystal films)

  • 김근영;윤석규;정일섭;박승배;윤대호
    • 한국결정성장학회지
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    • 제14권5호
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    • pp.193-198
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    • 2004
  • $(TbBi)_3(FeAIGa)_5O_{12}(TbIG)$, $(EuBi)_3(FeAIGa)_5O_{12}(EuIG)$, $(EuTbBi)_3(FeAIGa)_5O_{12}(EuTbIG)$ 가네트 막을 $PbO-B_2O_3-Bi_2O_3$ 융제를 사용하여 $(GdCa)_3(GaMgZr)_5O_{12}(SGGG)$ 기판 위에 liquid phase epitaxy(LPE) 방법으로 성장시켰다. 성장된 TbIG, EuIG, EuTbIG 가네트 막의 포화자계값은 각각 150 Oe, 950 Oe, 170 Oe를 보였으며, magnetic force microscope(MFM) 분석을 측정 한 결과 TbIG 막에서는 단일 자구가 관찰되었으며, EuIG와 EuTbIG 막에서는 다 자구가 관찰되었다.

White ACPEL Device with ZnS:Cu,Cl, $Tb_3Al_5O_{12}:Ce^{3+}$, and CaS:$Eu^{2+}$ Phosphors Using a Layered Structure

  • Park, Bong-Je;Seo, Hong-Seok;Ahn, Jun-Tae;Oh, Dae-Kon;Chung, Woon-Jin;Han, Ji-Yeon;Jang, Ho-Seong;Jeon, Duk-Young
    • ETRI Journal
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    • 제31권6호
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    • pp.803-805
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    • 2009
  • Improvement of the color rendering index (CRI) and luminance of a white alternate current powder electroluminescent (ACPEL) device has been attempted using ZnS:Cu,Cl, $Tb_3Al_5O_{12}$:Ce (TAG:Ce), and CaS:Eu phosphors with a layered structure. The device with TAG:Ce and ZnS:Cu,Cl phosphors showed a CRI of 75, with a luminance increase of about 30% depending on the thickness of the TAG:Ce. Further CRI improvement was attempted using CaS:Eu. When they were separately screen-printed, the CRI was increased up to 89 with no decrease in luminance.

Synthesis and photoluminescence of Ca3Si3O8F2: Ce4+, Eu3+, Tb3+ phosphor

  • Suresh, K.;PoornachandraRao, Nannapaneni V.;Murthy, K.V.R.
    • Advances in materials Research
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    • 제3권4호
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    • pp.227-232
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    • 2014
  • $Ce^{4+}$, $Eu^{3+}$, $Tb^{3+}$ co-doped $Ca_3Si_3O_8F_2$ phosphor was synthesized via solid state reaction method using $CaF_2$, $CaCO_3$ and $SiO_2$ as raw materials for the host and $Eu_2O_3$, $CeO_2$, and $Tb_4O_7$ as activators. The luminescent properties of the phosphor was analysed by spectrofluorophotometer at room temperature. The effect of excitation wavelengths on the luminescent properties of the phosphor i.e. under near-ultraviolet (nUV) and visible excitations was investigated. The emission peaks of $Ce^{4+}$, $Eu^{3+}$, $Tb^{3+}$ co-doped $Ca_3Si_3O_8F_2$ phosphor lays at 480(blue band), 550(green band) and 611nm (red band) under 380nm excitation wavelength, attributed to the $Ce^{4+}$ ion, $Tb^{3+}$ ion and $Eu^{3+}$ ions respectively. The results reveal that the phosphor emits white light upon nUV (380nm) / visible (465nm) illumination, and a red light upon 395nm / 535nm illumination. RE ions doped $Ca_3Si_3O_8F_2$ is a promising white light phosphor for LEDs. The emission colours can be seen using Commission international de l'eclairage (CIE) co-ordinates. A single host phosphor emitting different colours under different excitations indicates that it is a potential phosphor having applications in many fields.

Preparation and Photoluminescence Properties of $Ba_{1-x}M_xGa_2S_4:Eu^{2+}$ (M = Ca, Sr) Phosphor

  • Yoo, Hyoung-Sun;Kim, Sung-Wook;Han, Ji-Yeon;Park, Bong-Je;Jeon, Duk-Young
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.561-564
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    • 2008
  • $Ba_{1-x}M_xGa_2S_4:Eu^{2+}$ (M = Ca, Sr) phosphor was prepared for white light emitting diodes application. Photoluminescence (PL) emission and excitation bands were red-shifted with increase of Ca and Sr content due to the crystal field effect. Moreover, the PL intensity under 450 nm was increased by substitution of Ca and Sr.

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Changes in the Moisture Stability of $CaS:Eu^{2+}$ Phosphors with Surface Coating Methods

  • Yoo, Sun-Hwa;Kim, Chang-Keun
    • Macromolecular Research
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    • 제17권11호
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    • pp.907-911
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    • 2009
  • To improve the moisture stability of the $CaS:Eu^{2+}$ red phosphor, surface coatings with silica nanoparticles were performed using five different methods, i.e., $P_1$, $P_2$, $P_3$, $P_4$, and $P_5$. The phosphors were coated with silica nanoparticles using a dip coating method ($P_1$) and sol-gel method ($P_2$). The phosphors were coated using a solution containing silica nanoparticles and poly(1-vinyl-2-pyrrolidone), PVP, $(P_3$). The phosphors were also coated with silica nanoparticles by reacting with the 1-vinyl-2-pyrrolidone (VP) monomer ($P_4$) or by reacting with mixtures containing VP and tetraethylorthosilicate ($P_5$). A decrease in the photoluminescence (PL) intensity was observed regardless of the coating methods. However, the moisture stability of the phosphors was enhanced by the coating when aged in a temperature-controlled humidity chamber. Among these methods, the $P_4$ (or $P_5$) method exhibited the greatest increase in moisture stability of the phosphors. The coated phosphors showed a relatively constant intensity with aging time, whereas the uncoated phosphor showed a decrease.

Improving color gamut of white LED for LCD B/L application

  • Lee, H.J.;Yoo, J.S.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.1100-1102
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    • 2006
  • A three-band white LED was fabricated by combining a blue LED with SrGa2S4:Eu (green) and CaS:Eu (red) phosphors for improving the color gamut, which is favorable to full color image.

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비수용액에서 가벼운 란탄족 이온의 전기화학적 거동, 흐름 주입법에 의한 정량 및 중금속 이온의 킬레이트형 8-배위 착물의 광화학적 특성 연구 (제 2 보) : 계면활성제 존재하에서 Chromeazurol S를 사용하여 몇 가지 란탄이온의 흐름주입법에 의한 정량 (Studies on Electrochemical Behavior of Some Light Lanthanide Ions in Nonaqueous Solution, Flow Injection Determination and Photochemical Characterization of Heavy Metal Ion Chelate Eight Coordinated Complexes. (Part 2))

  • 강삼우;장주환;김일광;한홍석;조광희
    • 대한화학회지
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    • 제38권1호
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    • pp.50-54
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    • 1994
  • 흐름주입법에 의하여 분광광도법으로 몇 가지 가벼운 란탄족 원소를 정량하였다. Chromeazurol S는 양이온 계면활성제인 DTAB존재하에서 란탄족 이온과 착물을 형성한다. Tris 완충용액(pH 10.5)에서 이 착물의 최대흡수파장은 650 nm 에서 655 nm범위이고 몰흡광계수는 약 $1.8{\times}10^5\;L mol^{-1}cm^{-1}$였다. FIA에 의한 Nd(III), Eu(III) 및 Sm(III)의 검정곡선은 0.1 ~ 0.6 ppm에서 직선관계를 보였고, 이 검정곡선의 상관계수(${\gamma}$)는 0.9993이였다. 검출한계(S/N)는 Nd(III)과 Eu(III)에 대하여는 10 ppb이고, Sm(III)에 대하여는 20 ppb였다. 상대표준편차는 시료 0.4 ppm에 대하여 약 ${\pm}$1.2%이고, 시료의 분석 속도는 약 $50hr^{-1}$였다.

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