• Korean Journal of Materials Research
• /
• v.12 no.7
• /
• pp.555-559
• /
• 2002

Blue-emitting $Sr_{10}$($PO$)$_{6}$ $Cl_2$:$Eu^{2+}$ and $_{(Sr,Mg) }$ 10/($PO_4$)$_{6}$ $Cl_2$:$Eu^{2+}$ phosphor particles for application of long-wavelength UV LED were prepared by ultrasonic spray pyrolysis. The luminescence characteristics under long- wave-length ultraviolet of the $Sr_{10}$ ($PO_4$)$_{6}$ $Cl_2$:$Eu^{2+}$ and (Sr,Mg)$_{10}$ ($PO_4$)$_{6}$ $Cl_2$:$^Eu{2+}$ phosphor particles prepared by the spray pyrolysis were compared with that of the commercial product. The PL intensity of the $Sr_{10}$ ($PO_4$)$_{6}$ $Cl_2$:$Eu^{2+}$ particles prepared by the spray pyrolysis was lower than that of the commercial $Sr_{10}$ ($PO_4$)$_{6}$ $Cl_2$:$Eu^{2+}$ particles because prepared $Sr_{10}$ ($PO_4$)$_{6}$ $Cl_2$:$Eu^{2+}$ phosphor particles had porous structure and hollow morphology. However, the PL intensity of the (Sr,Mg)$_{10}$($PO_4$)$_{6}$ $Cl_2$:$Eu^{2+}$ phosphor particles prepared by the spray pyrolysis was 8% higher than that of the commercial one. The high brightness of $(Sr,Mg)_{10}$ ($PO_4$)$_{6}$ $Cl_2$:Eu$^{2+}$ phosphor particles prepared by spray pyrolysis is due to the dense structure and high crystallinity of particles. The TEX>$(Sr,Mg)<_{10}$ ($PO_4$)$_{6}$ /$Cl_2$:$Eu^{ 2+}$ phosphor particles had main emission peak t 448 nm under long- wavelength ultraviolet.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.33 no.1
• /
• pp.1-16
• /
• 2023

A non-rare earth-based strontium-aluminate red light emitting phosphor was synthesized by a solid-state reaction method and the effect of synthesis temperature and Mn⁴⁺ activator concentration on the photoluminescence characteristics of the phosphor was studied. The synthesized SrAl₂O₄:Mn⁴⁺ phosphor showed broad band absorption characteristics in the near-ultraviolet and blue regions with peaks at wavelengths of near 330 and 460 nm, and a triple band deep red emission consisted of three peaks at near 644, 658, and 673 nm. The SrAl₂O₄:Mn⁴⁺ phosphor synthesized at a temperature 1600℃ and a Mn⁴⁺ activator concentration of 0.5 mol% showed the strongest PL emission intensity, and concentration quenching was observed at concentrations higher than 0.7 mol%. FE-SEM and DLS particle size distribution analysis showed that the synthesized SrAl₂O₄:Mn⁴⁺ phosphor had a particle size distribution of 2~6.4 ㎛ and an irregular spherical shape with an average particle size of ~4 ㎛.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.1343-1346
• /
• 2008

$KSrPO_4$ and $Sr_3(Al_2O_5)Cl_2$ phosphors doped with $Eu^{2+}$ emit a blue and orange-yellow luminescence under ultraviolet (UV) excitation at ~ 400 nm, respectivel, which can be used for making white light emitting diodes.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07a
• /
• pp.737-739
• /
• 2005

To increase light efficiency, utilizing phosphors transfers ultraviolet ray to visible light and the fluorescent characteristic without change the electrical or optical design. Spreading phosphors on the surface of light bulb mirror can compensate the red and blue light to yield this correct white field after being stimulated by reflected ultraviolet ray.

• Bulletin of the Korean Chemical Society
• /
• v.25 no.10
• /
• pp.1585-1588
• /
• 2004

• Proceedings of the Materials Research Society of Korea Conference
• /
• 1997.05a
• /
• pp.98-98
• /
• 1997

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.576-577
• /
• 2008

ZnS:Cu,Cl blue-green phosphors were prepared by conventional solid state reaction. Copper activator of different concentrations was doped into ZnS structure at two firing steps. The luminescence characteristics dependent on $Cu^{2+}$ doping concentration of the phosphors has been investigated for inorganic electroluminescent device.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2000.01a
• /
• pp.29-30
• /
• 2000

CaS:Pb thin film used as phosphor layer in electroluminescent devices were deposited by an atomic layer deposition (ALD). The photoluminescence emission and excitation spectra were measured at 5 and 300K for the $CaS:Pb^{2+}$ phosphors with different Pb concentration from 0.001 at.% to 0.648 at.%. The emission spectra of these samples were characterized as UV emission and blue emission with the center of peak around 360 and 425nm, respectively. The UV emission was dominant at the low $Pb^{2+}$ concentration of 0.001 at%, whereas with increase of Pb concentration, the blue emission became a major component and to longer wavelength.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.411-412
• /
• 2007

EL (electro luminescent) is generally studied as a large size plane light emitting device and flexible light source because of it's simple manufacturing process. In this experiment, we manufactured flexible white emitting light source using Ni-foil with blue phosphor and color change materials. With increasing the thickness of color change material, the luminance of white emission is increased and the color coordinate of white color was shifted to pure white of (0.317,0.328) by strong emission of color change materials excited by blue excitation spectra. Also the luminance level was 30% higher in white emitting light device than blue only light source.

• The Korean Journal of Ceramics
• /
• v.3 no.2
• /
• pp.139-143
• /
• 1997

The photoluminescence characteristics of the zinc gallate have been investigated as a function of the composition and the firing atmosphere. Two distinct emission bands were observed whose peaks are 360 nm and 430 nm respectively. These emission bands are considered to be from two different emission centers. For $ZnO/Ga_2O_3$=49.3/50.7 or higher, 430 nm band is predominant and for $ZnO/Ga_2O_3$=49.2/50.8 or lower, 360nm band becomes predominant, whereas 430 nm band is almost completely suppressed. The shift of emission peak is though to be due to the change of the cation distribution with the zinc content in the spinel zinc gallate. Also, the emission centers responsible for the 360nm band are considered to be more efficient energy absorbers than the ones for the 430 nm band. Highly efficient green emitting phosphor was obtained by activating Zn-deficient zinc gallate with manganeses.