• 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.

• 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.

• 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.

• Journal of the Korean Society of Radiology
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• v.15 no.3
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• pp.391-399
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• 2021

Eu²⁺ doped polyphosphate NaSr(PO₃)₃ blue-emitting phosphors were synthesized by the conventional solid state method in a reductive atmosphere. The phase formation of NaSr(PO₃)₃ phosphors were characterized by using the X-ray powder diffraction (XRD) measurement. The photoluminescence emission and excitation spectra of the NaSr(PO₃)₃:Eu²⁺ phosphor, and decay curves were measured. Under the near-UV excitation, the phosphor exhibits a band emission around 420 nm assigned to the 4f⁶5d→f7(8S^7/2) transition of Eu²⁺. The temperature dependent emission spectra and decay curves were measured to elevate the thermal properties of the Eu²⁺ doped phosphors. The as-prepared NaSr(PO₃)₃:Eu²⁺ phosphors show a strong temperature dependent performance, which can serve as a promising temperature sensor.

• 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.

• 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.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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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.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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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 $(Ba,Sr)_2ZnS_3:Eu$.

• 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.

• Bulletin of the Korean Chemical Society
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• v.27 no.10
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• pp.1708-1711
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• 2006