• Title, Summary, Keyword: SrS:$Eu^{2+}$

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Synthesis of SrGa2S4 Phosphor and Its Luminescent Properties (SrGa2S4 형광체의 합성과 발광 특성)

  • Heo, Yeong-Deok;Sim, Jae-Hun;Do, Yeong-Rak
    • Journal of the Korean Chemical Society
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    • v.46 no.2
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    • pp.164-168
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    • 2002
  • SrGa$_2$S$_4$ : Eu is a green emitting phosphor which is applied for field emission display, and cathodoluminescence. Conventionally, SrGa$_2$S$_4$ : Eu is synthesized by solid state reaction, in which a mixture of SrCO$_3$, Ga$_2$O$_3$, and Eu$_2$O$_3$ is fired at high temperatures under flowing H$_2$S and Ar gases. In this study,SrGa$_2$S$_4$ : Eu phosphor is synthesized by using a decomposition method, where SrS, Eu complex, and Ga com-plex are used. The advantage of this method is that toxic H$_2$S gas and Ar gas are not used. The synthetic con-ditions and luminescent properties of SrGa$_2$S$_4$ : Eu phosphor are also investigated.

Cathodoluminescence and Longevity Properties of Potential Sr1-xMxGa2S4:Eu (M = Ba or Ca) Green Phosphors for Field Emission Displays

  • Ko, Ki-Young;Huh, Young-Duk;Do, Young-Rag
    • Bulletin of the Korean Chemical Society
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    • v.29 no.4
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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.

Synthesis and Luminescence Characteristics of SrGa2S4:Eu Green Phosphor for Light Emitting Diodes by Solid-State Method (고상법을 이용한 LED용 SrGa2S4:Eu 녹색 형광체의 합성 및 발광특성)

  • Kim, Jae-Myung;Kim, Kyung-Nam;Park, Joung-Kyu;Kim, Chang-Hae;Jang, Ho-Gyeom
    • Journal of the Korean Chemical Society
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    • v.48 no.4
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    • pp.371-378
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    • 2004
  • The $SrGa_2S_4:Eu^{2+}$ green emitting phosphor has been studied as a luminous device for CRT (Cathode Ray Tube) or FED (Field Emission Display) and EL (Electroluminescence). This phosphor, also, is under noticed for LED (Lighting Emitting Diode) phosphor, which makes use of excitation characteristics of long wavelength region. The $SrGa_2S_4:Eu^{2+}$ phosphor was prepared generally conventional synthesis method using flux. However, this method needs high heat-treated temperature, long reaction time, complex process and harmful $H_2S$or $CS_2$ gas. In this works, therefore, we have synthesized $SrGa_2S_4:Eu^{2+}$ using SrS, $Ga_2S_3$, and EuS as starting materials, and the mixture gas of 5% H2/95% N2 was used to avoid the $H_2S$or $CS_2$. We investigated the luminescence characteristic of $SrGa_2S_4:Eu^{2+}$ phosphor prepared in various synthesis conditions, performed post-treatment and sieving process for application to LED.

Luminescent Properties of Four-Band White Light Emitting Diodes (사파장 백색 발광 다이오드의 발광 특성)

  • Young-Duk Huh;Su-Mi Lim
    • Journal of the Korean Chemical Society
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    • v.47 no.4
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    • pp.370-375
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    • 2003
  • $BaMg_2Al_16O_27:Eu,\SrGa_2S_4:Eu$, and ZnCdS:Ag,Cl phosphors were chosen to produce blue, green, and red emissions, respectively, under excitation from a violet light emitting diode (LED). A four-band white LED was obtained by a combination of nonabsorbed violet emission from a violet LED and blue, green, and red emissions from $BaMg_2Al_16O_27:Eu,\SrGa_2S_4:Eu$, and ZnCdS:Ag,Cl phosphors. The luminescent properties of the four-band white LED were also discussed.

Preparation, Characterization and Photoluminescence Properties of Ca1-xSrxS:Eu Red-emitting Phosphors for a White LED

  • Sung, Hye-Jin;Cho, Young-Sik;Huh, Young-Duk;Do, Young-Rag
    • Bulletin of the Korean Chemical Society
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    • v.28 no.8
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    • pp.1280-1284
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    • 2007
  • A series of Ca1-xSrxS:Eu (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) phosphors were synthesized by solid-state reactions. The Ca1-xSrxS:Eu phosphors have a strong absorption at 455 nm, which corresponds to the emission wavelength of a blue LED. The emission peak of Ca1-xSrxS:Eu is blue shifted from 655 to 618 nm with increasing Sr content. The characteristics of Ca1-xSrxS:Eu phosphors make them suitable for use as wavelengthtunable red-emitting phosphors for three-band white LEDs pumped by a blue LED. In support of this, we fabricated a three-band white LED by coating SrGa2S4:Eu and Ca0.6Sr0.4S:Eu phosphors onto a blue LED chip, and characterized its optical properties.

Synthesis and luminescence properties of SrS:Eu red phosphors by solid state method

  • Kim, Jae-Myung;Kim, Kyung-Nam;Park, Joung-Kyu;Kim, Chang-Hae;Jang, Ho-Gyeom
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.640-643
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    • 2004
  • We have synthesized SrS:Eu red phosphor by solid state method and investigated to adopt a red phosphor for LEDs. The SrS:Eu phosphor shows broad emission band at 600nm region due to f-d energy transfer of $Eu^{2{\cdot}}$. Our results show that the SrS:Eu red phosphor exhibits the better luminescence efficiency than that of the industrially available product SrS:Eu phosphor.

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Superconductivty and Magnetic Properties of Tb-substituted $RuSr_2(Eu_{1.34}Ce_{0.66})Cu_2O_z$ (Tb이 치환된 $RuSr_2(Eu_{1.34}Ce_{0.66})Cu_2O_z$ 계의 초전도 및 자기적 특성)

  • Lee, H.K.;Lee, M.S.
    • Progress in Superconductivity
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    • v.14 no.2
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    • pp.110-115
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    • 2012
  • Samples with nominal compositions of $RuSr_2(Eu_{1.34-x}Tb_xCe_{0.66})Cu_2O_z$ (x = 0, 0.67) were prepared and their superconductivity and magnetic properties were compared to shed light on the effect of Tb substitution for Eu. X-ray diffraction measurements indicate that the Tb substitution resulted in a decrease in both a and c lattice parameters in consistent with ionic size difference between Eu and Tb. Contrary to the Tb-free sample, no superconducting transition behavior is observed in the Tb-sustituted sample. It is also found that the Tb substitution for Eu significantly increases the weak-ferromagnetic component of the field-cooled magnetic susceptibility as well as an increase in the magnetic ordering temperature. These results suggest that the magnetic state of the Ru sublattice is significantly affected by the Tb substitution for Eu.

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

  • Kakihana, Masato;Petrykin, Valery
    • 한국정보디스플레이학회:학술대회논문집
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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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Preparation and Optical Properties of $SrGa_2S_4$:Eu Phosphor

  • Do, Yeong Nak;Bae, Jae U;Kim, Yu Hyeok;Yang, Hong Geun
    • Bulletin of the Korean Chemical Society
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    • v.21 no.3
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    • pp.295-299
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    • 2000
  • The photoluminescence and cathodoluminescence of $SrGa_2S_4:EU$ phosphor were optimized with the process and chemical variables (activators, fluxes and reaction temperature) used in solid state reaction. Firing the powder with flux at $800^{\circ}C$ for 2hr gave the highest photoluminescence efficiency under near-UV excitation and the highest cathodoluminescence efficiency of 20.1 lm/W at 2 kV and 33.3 lm/W at 10 kV. The suitability of $SrGa_2S_4:EU$ for application as a phosphor in LCDs and FEDs is discussed.

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