• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1116-1119
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• 2008

We developed phosphorescent white OLEDs with high efficiency and color stability. By engineering device architecture in which confined excitons within the emissive layer by using adequate interlayer and balanced recombination of charge carriers by using stepwise hole transporting layer system, these WOLEDs showed power efficacy of 43.6 lm/W with CRI = 62 and 36 lm/W with CRI = 72 at $100\;cd/m^2$ without outcoupling enhancements.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.692-696
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• 2005

In an attempt to fabricate all inclusive display systems we are presenting a study on several elements that would be used as building blocks for all-on-board integrated applications on stainless steel foils. These systems would include in the same substrate all or many of the components needed to drive a flat panel OLED display. We are reporting results on both digital and analog circuits on stainless steel foils. Shift registers running at speeds greater than 1.0MHz are shown as well as oscillators operating at over 40MHz. Pixel circuits for driving organic light emitting diodes are presented. The device technology of choice is that based on poly-silicon TFT technology as it has the potential of producing circuits with good performance and considerable cost savings over the established processes on quartz or glass substrates (amorphous Silicon a-Si:H or silicon on Insulator SOI).

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.854-857
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• 2009

The concept of a microplasma current switch for a device operated in a current mode like organic light-emitting diodes, which features matrix addressability and current switching, is presented as well as its architecture and operational principle. To verify the concept, we have fabricated a 100 mm ${\times}$ 100 mm microplasma current switch panel with a cell pitch of $1080{\mu}m{\times}1080{\mu}m$. Moreover, the current-voltage measurements of the unit cell are performed for three different driving voltage amplitudes. They show the characteristic of an asymmetric floating double probe diagnosing plasmas.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2011년도 춘계학술대회 및 Fine pattern PCB 표면 처리 기술 워크샵
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• pp.106-107
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• 2011

Organic Light Emitting Diode(OLED), Optical Photovotaic Device(OPV)와 같은 유기소자에서 전극으로 적용되어지고 있는 Indium Tin Oxide (ITO) 박막의 유연성을 향상시키기 위하여 중간층으로 투명도(~80%)와 전도도(~1000 S/cm)가 우수한 PEDOT:PSS(PH1000)을 적용하였다. PEDOT:PSS(PH1000)의 적용으로 인하여 ITO 박막의 유연성이 현저히 개선됨과 동시에 PEDOT:PSS(PH1000)의 우수한 전도도로 인하여 보다 얇은 ITO의 두께에서도 우수한 면 저항(25 ${\Omega}/{\square}$ ~ 220 ${\Omega}/{\square}$) 및 비저항(3.75E-4 ${\Omega}{\cdot}cm$ ~ 4.40E-4 ${\Omega}{\cdot}cm$)의 값을 측정하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.442-443
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• 2007

We have studied new hole blocking layer for effective organic light emitting diodes. The device having a structure of ITO/2TNATA/$\alpha$-NPD/DPVBi : Rubrene(0.7%)/DPVBi/New Hole Blocking layer or BCP/$Alq_3$/LiF/Al has been used. The driving voltage of OLED with BCP(2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) or New HBL were 5.5V and 4.4V, respectively. As a result, new HBL rather than BCP has a good hole blocking ability.

• 한국전기전자재료학회논문지
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• 제27권6호
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• pp.377-382
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• 2014

We have investigated the effects of spacer layer inserted between blue and red doped emission layers on the emission and efficiency characteristics of phosphorescent OLEDs. N,N'-di-carbazolyl-3,5-benzene (mCP) was used as a host layer. Iridium(III)bis[(4,6-di-fluorophenyl)- pyridinato-N,$C^2$']picolinate (FIrpic) and tris(1-phenyl-isoquinolinato-$C^2$,N)iridium(III) [Ir(piq)3] were used as blue and red dopants, respectively. The emission layer structure was mCP (1-x) nm/mCP:$Ir(piq)_3$ (5 nm, 10%)/mCP (x nm)/mCP:FIrpic (5 nm, 10%). The thickness of mCP spacer layer was varied from 0 to 15 nm. The emission from $Ir(piq)_3$ and the efficiency of the device were dominated by energy transfer from mCP host and FIrpic molecules, and by diffusion of mCP host triplet excitons.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.781-784
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• 2005

We have developed technology to fabricate large-size active matrix organic light-emitting diode (AMOLED) displays with good color purity. Using these innovations, we have developed a 40inch diagonal WXGA AMOLED full color display. Because the TFT circuitry occupies a large portion of the pixel structure, an efficient white emission OLED is essential to integrate the device onto the active matrix backplane. The development of these technologies enables OLED displays to fulfill the requirements for larger size applications such as HDTVs

• 반도체디스플레이기술학회지
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• 제8권1호
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• pp.33-38
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• 2009

We have investigated the effect of the ambient gases on the characteristics of AZO thin films for the OLED (organic light emitting diodes) devices. These AZO thin films are deposited by rf-magnetron sputtering under different ambient gases (Ar, Ar+$O_2$, and Ar+$H_2$) at 300. In order to investigate the influences of the oxygen and hydrogen, the flow rate of oxygen and hydrogen in argon mixing gas has been changed from 0.2sccm to 1sccm and from 0.5sccm to 5sccm, respectively. The AZO thin films were preferred oriented to (002) direction regardless of ambient gases. The electrical resistivity of AZO film increased with increasing flow rate of $O_2$ under Ar+$O_2$ while under Ar+$H_2$ atmosphere the electrical resistivity showed minimum value near 1sccm of $H_2$. All the films showed the average transmittance over 80% in the visible range. The OLED device was fabricated with different AZO substrates made by configuration of AZO/$\acute{a}$-NPD/DPVB/$Alq_3$/LiF/Al to elucidate the performance of AZO substrate.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.186-189
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• 2006

The flexible organic thin film transistor (OTFT) array to use as a switching device for an organic light emitting diode (OLED) was designed and fabricated in the microcontact printing and room temperature process. The gate, source, and drain electrode patterns of OTFT were fabricated by microcontact printing process. The OTFT array with dielectric layer and organic active semiconductor layer formed at room temperature or at a temperature lower than $40^{\circ}C$. The microcontact printing process using SAM and PDMS stamp made it possible to fabricate OTFT arrays with channel lengths down to even submicron size, and reduced the fabrication process by 10 steps compared with photolithography. Since the process was done in room temperature, there was no pattern shrinkage, transformation, and bending problem appeared. Also, it was possible to improve electric field mobility, to decrease contact resistance, to increase close packing of molecules by SAM, and to reduce threshold voltage by using a big dielectric.