• Journal of the Korean Ceramic Society
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• v.41 no.5
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• pp.406-409
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• 2004

A blue phosphor(ZnS:Cu) is manufactured by solid state reaction for ACPEL(AC powder EL). The effect of artificial defect on phosphor surface on the ZnO phase conversion and resulting luminescence have been studied. It was found that ZnS:Cu could converse to cubic phase more easily due to the formation of artificial defect on 1st fired phosphor by ball-milling process, resulting in improvement of luminescence of phosphor phosphors under the driven EL condition. We found out an optimized ball-mill condition through considering effect of each ball-mill conditions such as milling time and milling rpm on defect. Also we determined relationship between emission luminescence and phase of phosphor based on analyses of crystal structures of phosphors. A significant improvement above 30% was observed in electroluminescence by the artificial defect on ZnS:Cu phosphors compared to non-treated phosphors.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.2
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• pp.64-67
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• 2004

In this paper, to discover the brightness improvement of ZnS:Cu powder electroluminescence (EL), a new structure is proposed in which phosphor and dielectric are mixed between electrodes. Dielectric and phosphor material are BaTiO$_3$ and ZnS:Cu, respectively. The effect of the mixed layer on EL sample is considered the improvement of source efficiency. Although the number of electrons introduced into the phosphor increases only modestly, the high electric field region of phosphor grains increases comparatively in the characteristics of brightness-voltage. Furthermore, the relaxation occurs through leading and trailing edge pairs, which is relatively efficient in characteristics of decay time. With these results, we found that the brightness of newly proposed ZnS:Cu powder electroluminescence was 167.24 cd/$m^2$ at ac voltage of 100V and frequency of 400Hz.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1537-1538
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• 2007

ZnS:Cu,Cl phosphor was synthesized by solid-liquid state reaction with two firing steps. Each stage of the process was carefully monitored so that the final product was comparable to commercially-available phosphor. The effect of $Cu^{2+}-doping$ concentration has been investigated on the luminescence characteristics of ZnS:Cu,Cl blue-green phosphors for inorganic electroluminescent device.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.403-406
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• 1998

Electroluminescence(EL) come from the light emission obtained by electrical excitation energy passing through a phosphor layer under applied high electrical field. The preparation and characterizations of light emitting ACPEL(alternating-current powder electroluminescent) cell based on two kinds of phosphor mixed ZnS:Mn, Cu and ZnS:Cu phosphor. Basic structure is ITO/Mixed Phosphor/insulator/Al sheet, each layer was mixed by binder, which concentration 11p for phosphor, 8p for insulator. Dielectric properties was investigated first and emission properties of P-LED based on ZnS:Mn,Cu/ZnS:Cu,Br mixture. Emission spectra exhibits two kinds of main peaks at 100V, 1kHz sinusoidal excitation.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.125-125
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• 2009

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.424-425
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• 2006

Zinc sulfide is a well-known host material of phosphor emitting different radiations dependent on different doping impurities of metallic ion. It emits green, blue, orange-yellow or white colors by doping with activators such as copper, silver, manganese and so on. In this study, manganese, copper and chlorine doped ZnS phosphor (ZnS:Mn,Cu,Cl) was synthesized by solid-state reaction method. The optical properties were investigated according to different concentrations of sulfur and activators used during the synthesis process.

• Journal of Surface Science and Engineering
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• v.41 no.4
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• pp.169-173
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• 2008

The objective of this study is to coat the $SiO_2$ layer uniformly on the ZnS:Cu phosphors by using Sol-Gel method. From results of SEM micrographs observation, XRD and XPS analysis, it could be confirmed that $SiO_2$ layer was relatively well coated on ZnS:Cu particles. $Ag_2S$ was used as a decoding chemical to analyze the dense and uniform coating performance of $SiO_2$ layer on phosphor particles. It could be concluded that phosphors synthesized from our two step replacement method showed strong blue peak comparing to other method and rather weak green peak also. Obtained particle size of phosphors were about 20m diameter. Luminescence properties of the phosphors were examined by photoluminescence spectra at the excitation wavelength of 270 nm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.528-531
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• 2000

ZnS:Cu phosphor used on powder electroluminescent device has a green emission in low frequency and a blue emission in high frequency. In this paper, to obtain the powder electroluminescent device of the blue emission in low frequency, the emission properties with mixed the ratio between phosphor and dye was investigated. The mixed ratio of the dye was from 0 to 5 weight percent. To inquire into the blue emission, the emission spectrum, the CIE coordinate system and the brightness were measured.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2001.11a
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• pp.13-16
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• 2001

In this paper, the emission and aging properties of ZnS:Cu electroluminescent device were experiment respectively at room temperature and 7$0^{\circ}C$ relative humidity 100%. ZnS:Cu and BaTiO$_3$were respectively used for phosphor and dielectric. While AC 100V on 400Hz frequency were applied to the devices at room temperature and 70$_3$relative humidity 100%, the change of brightness were measured and compared. The surface of aged devices were investigated by scanning electron microscope. With the continuously operated environment of room temperature and 7$0^{\circ}C$ relative humidity 100%, the decay time were measured and the dark spot and aging status on the surface of the device were investigated. ZnS:Cu electroluminescent properties were deteriorated by the Increased temperature and humidity. Also the deteriorated properties were confirmed by the brightness and surface chanties of device, and the aging mechanism from the simulation on sulfur vacancy and deep tracts density.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.391-394
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• 1998

Electroluminescence is the light emission obtained by an electrical excitation energy passing through a phosphor under an applied high electrical field. EL are paid much attention on flat panel display as a backlight and indicator, which are divided into ACPRL(alternating-current powder electroluminescent) and ACTFEL(alternating-current powder electroluminescent). In this paper, Electric and emission properties on ACPEL are investigated based on ZnS:Cu phosphor. The basic structure on this is ITO glass/phosphor/insulator/ backelectrode, CR-M which has high efficiency on thermal properties and dielectric Properties was introduced and BaTiO$_3$ as a insulating layer in order to increase app1ied electric field on phosphor. Changing on Dielectric and emission Properties was caused by a different viscosity of binder which filled on space between phosphor particle. 60cd/$m^2$ under 60V, 2kHz sinusoidal was gotten from ACPELD prepared in this work.