• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.839-842
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• 2009

In this paper, chalcogenide glasses material(Se, Te, Sb) is firstly used as encapsulation layer of OLEDs under high vacuum of $10^{-4}$Pa. In the experiments, properties of OLEDs encapsulated by Se, Te, Sb thin film is compared with that of device encapsulated by traditional method. It is found that Se, Te, Sb film can extend lifetime of devices to 1.4, 2, 1.3 times respectively. Chalcogenide glasses film as encapsulation layer has little effect on some characteristics of device. The research indicated that OLEDs can be well protected upon applying Se, Te, Sb film as encapsulation layer. It is clear that it can prolong the lifetime obviously.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.192-195
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• 2009

We developed highly efficient blue PHOLEDs with reduced roll-off by using a mixed host structure. The balanced charge carrier injection and the distributed recombination zone within emissive layer resulted in a highly stable efficiency roll-off with quantum efficiencies of 20.1 and 18.1 % at a luminance of 1000 and 10000 cd/$m^2$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.253-257
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• 1998

Organic-based electroluminescent devices have attracted lots of interests because of their possible application as large-area flat pan디 display. In this study, current-voltage (I-V) characteristics of MEH-PPV thin films was investigated using various metal as a top electrode, where MEH-PPV thin films were prepared on 170 substrate by spin coating method and various metal such as Al, Ag, In, MgIn was deposited on MEH-PPV thin films as a top electrode.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.553-555
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• 2005

본 논문은 모든 항전장비 가운데서도 조종사의 신속한 상황인식과 수많은 정보의 처리를 위하여 지속적으로 발전이 이루어지고 있는 조종석 디스플레이 시스템의 개량형 설계를 제안한다. 현재 항공기 조종석 시스템은 아날로그식 계기판과 함께 다수의 2-D 컬러 디스플레이를 배열한 모델을 사용하고 있다. 본 논문에서 차세대 조종석을 위해 제안하는 시스템은 미공군에서 개발 중인 방식을 도입하여 3-D와 2-D를 흔용한 소수의 대형 디스플레이로 디지털 신호만을 사용한 시스템에 OLED(Organic Light Emitting Diodes) 소자를 적용한 것이다. 이 시스템은 상용칩을 수용한 고성능의 컴퓨터 시스템을 이용하여 초당 50,000개의 3-D triangle을 최신화하여 밝은 지형과 어두운 지형 투명도, 지형특성, 비가시적 지형을 시현한다. 본 설계의 구현을 통하여 고성능의 신호 집약적 시스템 설계의 우수성과 차세대 소자로 각광받는 OLED 디스플레이 채택을 통한 디스플레이 시스템 상의 가시도 향상 및 중량감소 등의 효과가 있어 조종석 디스플레이 시스템의 실용도가 개선들 수 있음을 제안하였다.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1357-1358
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• 2006

Indium tin oxide (ITO) thin film is a transparent electrode, which is widely applied to solar battery, illuminators, optical switches, liquid crystal displays (LCDs), plasma display panels (PDPs), and organic light emitting displays (OLEDs) due to its easy formation on glass substrates, goof optical transmittance, and good conductivity. ITO thin film is generally fabricated by various methods such as spray, CVD, evaporation, electron gun deposition, direct current electroplating, high frequency sputtering, and reactive DC sputtering. However, some problems such as peaks, bumps, large particles, and pin-holes on the surface of ITO thin film were reported, which caused the destruction of color quality, the reduction of device life time, and short-circuit. Chemical mechanical polishing (CMP) processis one of the suitable solutions which could solve the problems.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.12a
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• pp.114-118
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• 2006

We investigated the transient electroluminescence (EL) and modulation characteristics of red organic light-emitting diodes (OLEDs), which consist with 4-(dicyanomethylene)-2-i -propyl-6-(1,1,7,7-tetramethyljulolidyl-9-cnyl)-4H-pyran (DCJTI) and rubrene doped into tris(8-hydroxyquinoline)aluminum ($Alq_3$). The transient EL waveforms showed two components, the overshooting peak and constant component, indicating that the excess amount of accumulated charges simultaneously recombine at the onset moment. This overshooting effect reduced the rise time of transient EL and enhanced the optical output of OLEDs when the pulse voltage applied to the device. We demonstrated that the red OLEDs could be use for the high-speed switching application by driving at more than 100 MHz and transmitting the video signals utilized as the electro-optical conversion device

• Journal of Information Display
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• v.5 no.1
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• pp.28-33
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• 2004

A high voltage NMOSFET is proposed to drive top emission organic light emitting device (OLED) used in the organic electroluminescent (EL) display on the single crystal silicon substrate. The high voltage NMOSFET can be fabricated by utilizing a simple layout technique with a standard CMOS logic process. It is clearly shown that the maximum supply voltage ($V_{DD}$) required for the pixel-driving transistor could reach 45 V through analytic and experimental methods. The high voltage NMOSFET was fabricated by using a standard 1.5 ${\mu}m$, 5 V CMOS logic process. From the measurements, we confirmed that the high voltage NMOSFET could sustain the excellent saturation characteristic up to 50 V without breakdown phenomena.

• Bulletin of the Korean Chemical Society
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• v.31 no.2
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• pp.389-396
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• 2010

In this paper, we reported the synthesis and electroluminescent properties of blue fluorescent styrylamine derivatives end-capped with a diphenylvinyl group. A new series of styrylamine derivatives have been synthesized via the Horner-Wadsworth-Emmons reaction. To explore electroluminescent properties of these molecules, multilayer organic lighte-mitting devices with the configuration of ITO/NPB/1-5 doped in MADN/Bphen/Liq/Al were fabricated. All devices exhibited blue emissions with good EL performances. Among those reported herein, the device using dopant 5 exhibited a maximum luminance of $24,000\;cd/m^2$ at 11.0 V, a luminous efficiency of 12.5 cd/A at $20\;mA/cm^2$, a power efficiency of 6.50 lm/W at $20\;mA/cm^2$, and $CIE_{x,y}$ coordinates of (x = 0.173, y = 0.306) at 8.0 V, all of which demonstrate the superiority of these materials in blue OLEDs.

• Journal of the Semiconductor & Display Technology
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• v.7 no.3
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• pp.5-9
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• 2008

New devices with structure of ITO/2TNATA/NPB/TCTA/CBP:7%Ir(ppy)$_3$/BCP/ETL/LiF/Al were proposed to develop high luminous green phosphorescent organic light emitting diodes and their electroluminescent properties were evaluated. The experimental devices were divided into two kinds according to the material ($Alq_3$ or SFC137) used as an electron transport layer (ETL). Luminous intensities of the devices using $Alq_3$ and SFC137 as electron transport layers were 27,500 cd/$m^2$ and 51,500 cd/$m^2$ at an applied voltage of 9V, respectively. The current efficiencies of both devices were similar as 12.6 cd/A under a luminance of 10,000 cd/$m^2$, while showed slower decay in the device with SFC137 as an ETL according to the further increase of luminance. Current density and luminance of the device with SFC137 as an electron transport layer were higher at the same voltage than those of the device with $Alq_3$ as an ETL.

• Laser Solutions
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• v.13 no.1
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• pp.11-15
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• 2010

Indium tin oxide (ITO) provides high electrical conductivity and transparency in the visible and near IR (infrared) wavelengths. Thus, it is widely used as a transparent electrode for the fabrication of liquid crystal displays (LCDs) and organic light emitting diode displays (OLRDs), photovoltaic devices, and other optical applications. Lasers have been used for removing coating on polymer substrate for flexible display and electronic industry. In selective removal of ITO layer, laser wavelength, pulse energy, scan speed, and the repetition rate of pulses determine conditions, which are efficient for removal of ITO coating without affecting properties of the polymer substrate. ITO coating removal with a laser is more environmentally friendly than other conventional etching methods. In this paper, pattering of ITO film from polymer substrates is described. The Yb:KGW femtosecond laser processing system with a pulse duration of 250fs, a wavelength of 1030nm and a repetition rate of 100kHz was used for removing ITO coating in air. We can remove the ITO coating using a scanner system with various pulse energies and scan speeds. We observed that the amount of debris is minimal through an optical and a confocal microscope, and femtosecond laser pulses with 1030nm wavelength are effective to remove ITO coating without the polymer substrate ablation.