• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.799-802
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• 2005

This paper described a 2.2" $QCIF^+$ ($176{\times}RGB{\times}220$) active matrix organic light-emitting diode display (AMOLED) using low-temperature poly-silicon (LTPS) technology. We have designed the OLED pixel to match the OLED material characteristic with COG specification and optimized pixel structure to improve color gamma adjustment and simplify signal complexity.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.522-523
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• 2005

Top emission OLED 소자에 사용되는 ITO(Indium-Tin-Oxide)의 저항을 개선하여 보다 낮은 저항을 가지는 전극을 제작하기 위해 AZO(ZnO-Ag-ZnO)를 제작하였다. AZO박막은 기존의 ITO박막이 수십 $\Omega$을 나타내던 것과 비교하여 $8\Omega$으로 매우 낮은 저항을 나타내었다. 투과율은 84%로 기존의 ITO박막과 유사한 성능을 나타내었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.485-486
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• 2006

Top emission OLED 소자에 사용되는 ITO(Indium-Tin-Oxide)의 저항을 개선하여 보다 낮은 저항을 가지는 전극을 제작하기 위해 AZO(ZnO-Ag-ZnO)를 제작하였다. AZO박막은 기존의 ITO박막이 수십 $\Omega$을 나타내던 것과 비교하여 $8{\Omega}$으로 매우 낮은 저항을 나타내었다 투과율은 84%로 기존의 ITO박막과 유사한 성능을 나타내었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.6
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• pp.861-866
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• 2018

In OLED (Organic Light-Emitting Diode) manufacturing, the aging process increases the manufacturing efficiency and measures the correction value to correct the aging. The correction value for correcting the aging of the OLED can be applied to the driving signal. The OLED aging process measures the current after outputting the light for a predetermined time according to the preset driving signal and temperature. In the OLED manufacturing process, aging is applied for non-uniformity by deposition and temperature. This time has little effect on OLED efficiency reduction. Heating devices and signal generation systems are required to create the conditions necessary for aging. The results measured by the heating system and signal generation system can be used as a basis for evaluating power requirements, uniformity and efficiency in OLED manufacturing. In this paper, we propose and implement a configuration for interlocking the driving signal generation and heating system for practical OLED aging correction.

• Journal of the Semiconductor & Display Technology
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• v.5 no.3 s.16
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• pp.23-27
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• 2006

Recently, Top emission organic light-emitting diode (TEOLED) has been attracted by their potential application for the development of flat panel display (FPD). We have fabricated the high luminance top emission organic-emitting diode (TEOLED) using dual cathode layer and three top emitting structure. These devices were characterized by electroluminescence (EL) and current density-voltage (J-V) measurements. After compared it with Au anode structure, luminance of the device using dual anode was better than using without Al device. Consequently, Al layers are very good candidates for a promising electron-injecting buffer layer for top emission light-emitting diode (TEOLED).

• Journal of IKEEE
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• v.26 no.2
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• pp.205-210
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• 2022

We demonstrated roll-to-roll microcontact printed (mCP) microlens array (MLA) to enhance the light extraction of organic light emitting diodes (OLEDs). The commercially provided microlens array is used as a template for polydimethylsiloxane (PDMS) roll stamp. The fluorinated film is formed on the PDMS roll stamp from fluorinated ink with low boiling point and printed onto the bottom side of the organic light emitting diode without high pressure and high thermal treatment. With optimized concentration of ink, the pattern which is almost identical to that of the template MLA was successfully printed. Due to the structure and low optical absorbance of microcontact printed MLA, the external quantum efficiency of OLED was improved by about 18%.

• Current Optics and Photonics
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• v.6 no.3
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• pp.227-235
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• 2022

To investigate the aging-related physiological functions of organic light-emitting diodes (OLEDs), we examined mRNA expression changes in aging-related genes due to oxidative stress inhibition by 630-nm red light OLEDs. As a result of irradiating 630-nm OLED with an intensity of 5 mW/cm² for 15 min, the viability of dermal fibroblasts significantly increased by 1.3-fold. In addition, reactive oxygen species generated by H₂O₂ were significantly reduced about 4.9-fold by irradiation with 630-nm OLED. Quantitative reverse-transcription polymerase chain reaction results showed that 630-nm OLEDs altered aging-related gene mRNA expression levels through antioxidant activity. The mRNA expression levels of matrix metalloproteinase1 (MMP1) and MMP9 decreased significantly, by about 2.2- and 2.5-fold, compared to the control group, whereas those of collagen, type I, and alpha 1 increased significantly, by 4.9-fold. The mRNA expression levels of cancer suppression genes p16 and p53 in dermal fibroblasts were also significantly reduced by 630-nm OLED irradiation, by about 1.4- and three-fold, respectively, compared to the control. Overall, it was confirmed that 630-nm OLED irradiation lowered the level of ROS formation induced by H₂O₂ in dermal fibroblasts, and that this antioxidant effect could regulate the mRNA expression levels of aging- and tumor suppression-related genes. This study shows a link between 630-nm OLED irradiation and anti-aging physiological functions such as antioxidant function, and suggests the potential of OLEDs as a useful light source for skin care.

• Journal of the Semiconductor & Display Technology
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• v.21 no.2
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• pp.7-10
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• 2022

A functional polyethylene terephthalate substrate to increase light extraction efficiency of organic light-emitting diodes is studied. We formed nano-structured PET surfaces by controlling the power, gas, and exposure time of the linear ion-beam. The haze of the polyethylene terephthalate can be controlled from 0.2% to 76.0% by changing the peak-to-valley roughness of nano structure by adjusting the exposure cycle. The treated polyethylene terephthalate shows average haze of 76.0%, average total transmittance of 86.6%. The functional PET increases the current efficiency of organic light-emitting diodes by 47% compared to that of organic light-emitting diode on bare polyethylene terephthalate. In addition to polyethylene terephthalate with light extraction performance, by conducting additional research on the development of functional PET with anti-reflection and barrier performance, it will be possible to develop flexible substrates suitable for organic light-emitting diodes lighting and transparent flexible displays.

• 전자공학회논문지 IE
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• v.43 no.2
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• pp.1-6
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• 2006

The white organic light emitting diode(OLED) with two-wavelength was fabricated using the DPVBi of blue emitting material and a series of orange colar fluorescent dye(Rubrene) by vaccum evaporation processes. The basic structure of OLED was ITO/TPD$(225{\AA})$/DPVBi/Rubrene/BCP$(210{\AA})/Alq_3(225{\AA})/Al(1000{\AA})$. We analyzed the fabricated device through the changes of the DPVBi and Rubrene layer's thickness. We obtained the white OLED with the CIE coordinate of the device was (0.29, 0.33) and luminescence of $1000cd/m^2$ at applied voltage of 15V when 4he thickness of DPVBi layer was 210${\AA}$ and the thickness of Rubrene layer was 180${\AA}$.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.9
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• pp.1-10
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• 2002

We have done various treatments of indium tin oxide (ITO) surface for organic light-emitting diodes (OLEDs), and investigated the surface states by different surface treatments using atomic force microscopy (AFM) and Auger electron spectroscopy (AES). We have fabricated OLEDs deposited by ultra-high vacuum molecular beam deposition system and studied the characteristics of the OLEDs. We have observed the dramatical improvement of the performance of OLEDs fabricated on ITO substrates treated by $O_2$ plasma treatment reduces the carbon comtamination of ITO surfaces and increases the work function of ITO.