• Journal of the Korean Applied Science and Technology
• /
• v.25 no.2
• /
• pp.175-195
• /
• 2008

Recent years have brought remarkable developments in white light emitting devices (WLEDs) and white organic light-emitting devices (WOLEDs). However, their efficiency, CIE values, CRI and lifetime are still not ideal. This review covers detailed discussion about syntheses of organometallic complexes, inorganic phosphors and quantum dots used in WLEDs, WOLEDs and their electroluminescent properties until December 2007.

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.1132-1133
• /
• 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.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.207-210
• /
• 2009

According to the recent demand for materials for use in various displays and solid state lightings, new phosphors with improved performance have been pursued consistently. Multi objective genetic algorithm assisted combinatorial material search (MOGACMS) strategies have been applied to various multi-compositional inorganic systems to search for new phosphors and to optimize the properties of phosphors.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.121-124
• /
• 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 $(Ba,Sr)_2ZnS_3:Eu$.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.08a
• /
• pp.156-156
• /
• 2011

Nanocrystalline $Ca_2Gd_8Si_6O_{26}$ (CGS) : $Sm^{3+}$ and CGS : $Tb^{3+}/Sm^{3+}$ phosphors were prepared by solvothermal reaction method for light emitting diode (LED) and field emission display (FED) applications. The XRD patterns of these phosphors confirmed their oxyapatite structure in the hexagonal lattice. The visible luminescence properties of these phosphors were investigated by exciting with ultraviolet (UV) or near-UV light and low voltage electron beam. The photoluminescence (PL) properties of $Ca_2Gd_8Si_6O_{26}$ (CGS) : $Sm^{3+}$ and CGS : $Tb^{3+}/Sm^{3+}$ phosphors were investigated as a function of $Sm^{3+}$ concentration. Cathodoluminescence (CL) properties were examined by changing the acceleration voltage. The CGS : $Sm^{3+}$ showed the dominant orange emission due to the $^4G_{5/2}{\rightarrow}^6H_{7/2}$ transition. The CGS : $Tb^{3+}/Sm^{3+}$ phosphor showed the green, white and orange emissions when excited with 275, 378, and 405 nm wavelengths, respectively. The chromaticity coordinates of these phosphors were comparable to or better than those of standard phosphors for LED or FED devices.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.56-59
• /
• 2009

In the nineties the invention of the InGaN blue LED has innovated illumination technology. Currently LCD backlighting and more and more general lighting applications are based on white LEDs comprising of inorganic phosphors and blue emitting InGaN chip. Well established phosphor materials are ortho silicates and garnets like yellow emitting YAG:Ce. In our paper we demonstrate that garnet materials also allow for green light emission for both, general lighting and backlighting LED applications.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.06a
• /
• pp.461-462
• /
• 2008

$BaMgAl_{10}O_{17}$:Mn, $Eu^{2+}$ green phosphors has been synthesized by the solid state reaction. Green phosphors of nano-size were manufactured in short time by shake method. which were easily manufactured respectively general method. Green phosphors of nano size were control additive, size of $ZrO_3$ ball, shake time and weight of ball in toluene. In result that green phosphors were obtained particle size of 140nm~150nm. The characteristics of fired samples were obtained by 365nm and 380nm excitation source under ultraviolet. In result that the highest PL intensity were observed in wavelength of 365nm.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.34D no.2
• /
• pp.27-37
• /
• 1997

Photoluminescent and cathodoluminescent charcteristics of inorganic luminescent materials were investigated ot develop possible phosphors for thin film electroluminescent (TFEL) device applications. Mg, Zn, and Photoluminescent and cathodoluminescent charcteristics of inorganic luminescent materials were investigated ot develop possible phosphors for thin film electroluminescent (TFEL) device applications. Mg, Zn, and $Si_3N_4$ powders were used to synthesize $(Mg_xZn_{1-x})SiN_2$ host materials. $Tb_4O_7$ and $Eu_2O_3$ powdrs were added as luminescent centers. Very sharp emission spectra of $Tb^{3+}$ ions were observed from $Mg._5Zn._5SiN_2:Tb$ sampels sintered at $1400^{\circ}C$ for an hour and the maximum intensity of emission spectra occured at wavelength of 550nm (green light). Synthetic conditions of $(Mg_xZn_{1-x})SiN_2:Eu$ phosphors were optimized for the hghest luminescence. The Eu concentrations were varied from 0.2% to 1.6%. Before firing, the powders were mixed using ballmills, methanol, acetone, or D.I. water. The Mg/Zn ratio also were varied from x=0.3 to x=0.7. The maximum PL intensity was obtained from a sample with 1.2% Eu concentration and the powder was mixed with methanol and dried before firing. The maximum intensity of the emission spectra occurred t the wavelength of 470nm(blue light). TFEL devices fabricated by using sputter deposition of $(Mg._3Zn._7)SiN_2:Eu$ phosphor layer showed yellowish white emission at the phosphor field of 2MV/cm.

• 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.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2007.11a
• /
• pp.75-76
• /
• 2007

ZnS:Cu,Cl phosphor was coated by solid-gel reaction with $SiO_2$ outside layer. The effect of $Cu^{2+}$-doping concentration has been investigated on the luminescence characteristics of ZnS:Cu,Cl blue-green phosphors for inorganic electro luminescent device. Also, SiO2 coated layers' effect on luminescence characteristics. Evaluation of luminescence characteristics dependent on the synthesis conditions is important to get high-performance phosphors properties. EL and PL properties such as luminescence intensity and chromaticity of ZnS:Cu,Cl phosphors synthesized with different concentration of activator, $Cu^{2+}$, were analysed separately