• Title/Summary/Keyword: Powder type electroluminescent device

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Emission Characteristics of Power Type Electroluminescent Device (분산형 전계발광 소자의 발광 특성)

  • 권순석;임기조;박수길;김현후;류부형;김용주
    • Electrical & Electronic Materials
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    • v.10 no.2
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    • pp.150-155
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    • 1997
  • Powder type electroluminescent device(P-ELD) in this study was prepared by printing method. P-ELDs were basically composed of phosphor, insulator and transparent conducting layer. The phosphor powder was prepared by sintering the mixture of ZnS as a host, Cu as an activator, and NaCl as a flux for co-activator and enhancement of growth of the phosphor particles. The phosphor layer was made by printing the paste of the cyanoethylpullan as a binder and the ZnS system phosphor powder. In order to evaluate the luminescence characteristics of ZnS P-ELD, applied voltage - luminance(V-L), frequency-luminance(f-L), and relative luminance spectra(L- .lambda.) characteristics were measured. The experimental results show that luminance increased with increasing the applied voltage and frequency. It can be explained in terms of the potential barrier formed between ZnS and CuS. Two emission peaks in luminance-wavelength spectra measured at applied voltage of 100 $V_{rms}$ were observed at 500nm as a primary peak and 460nm as a secondary peak, respectively.y.

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A Study on Dot-Matrix Display using Powder Electroluminescent Device with High Brightness (고휘도 후막 전계발광소자을 이용한 Dot-Matrix Display에 대한 연구)

  • Lee, Jong-Chan;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 1998.07d
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    • pp.1255-1257
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    • 1998
  • In this study,$ 5{\times}5$ dot-matrix display was implemented with powder electroluminescent device (PELD). Generally PELD which have a luminance from powder phosphor with electric field, inserted phosphor and dielectric layer between electrodes is basic structure. To make high brightness PELD compared to conventional device, new type of PELD was proposed as follows. New PELD had only one layer, which was mixed phosphor (ZnS:Cu) and dielectric (BaTiO3) material appropriately between electrodes. To compare and estimate the conventional and new type of PELD, the EL spectrum, transferred charge density, brightness and decay time was measured. As above result, we fabricated a hish brightness $ 5{\times}5$ dot-matrix display with new type of PELD. Its brightness was 6400 $cd/m^2$ at 200 V, 400Hz.

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A Study on Powder Electroluminecscent Device for High Brightness (고휘도 후막 전계발광소자에 관한 연구)

  • Oh, Joo-Youl;Lee, Jong-Chan;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 1998.07d
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    • pp.1382-1384
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    • 1998
  • Electroluminescence is occurred when phosphor is located in electric field. Object of this research show new type of powder electroluminescent device (PELD) for high brightness compared with conventional PELD. New type of PELD structured as follow ITO/phosphor + dielectric/Silver paste). To investigate optical properties of PELDs, EL spectrum, CIE coordinate system, Brightness of PELDs was measured. The suitable ratio between phosphor and dielectric in new type of PELD was 7:3(phosphor:dielectric). At 200 V 400 Hz, new type of PELD which had ratio of 7:3 was 5700 cd/$m^2$.

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Organic Dispersion Type Back Light EL Display Device as a New Light Source (신광원 유기분산형 백라이트 EL 디스플레이 소자)

  • 임인호;박종주;장관식;정회승;박창엽
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.14 no.1
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    • pp.1-6
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    • 2000
  • In this paper, organic dispersion type back light EL(Electroluminescent) devices were manufactured using Ethyl hydroxy ethyl cellulose as organic binder, ZnS:Cu as phosphor powder and $BaTiO_3$ as dielectrics by screen printing method, which are focused on as a new light source. The properties of the fabricated organic dispersion type back light EL devices were showed $1.98[mA/\m^2]$ of current density, 0.075[W] of power consumption, 7.1[nF] of capacitance at $25[^{\circ}C]$, 100[V], 400[Hz], respectively. Also brightness of the fabricated device was revealed $20~110[cd/\m^2]$ at 50~150[V] and the change of color was shoed bluish green of x=0.1711, y=0.3676 which are color coordinate by CIE.

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Frequency Effect on Electrical and Optical Characteristics in Blue-Green Emitting P-ELD (청녹색 발광 분산형 전계 발광 소자의 전기적 및 광학적 특성에 미치는 주파수 효과)

  • 권순석;유장열;한상완
    • Journal of the Korean Institute of Telematics and Electronics T
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    • v.36T no.3
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    • pp.1-6
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    • 1999
  • The preparation and electrical or optical characteristics of blue-green emitting powder type electroluminescent device(P-ELD) are described. In V-I and Y-L characteristics, current and luminance are increased with increasing frequency and voltage. Luminance was shown 840 cd/$\textrm{m}^2$ at operating condition of 20 kHz, 150 V It can be explained by eqivalent circuit of P-ELD.

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