• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
• /
• pp.1294-1296
• /
• 2005

We have fabricated white organic light emitting diodes. To obtain balanced white emission and improve the efficiency of devices, thin electron blocking layer (TEBL) was inserted between the emitting layers. We showed that the effective injection of electrons through the optimization of TEBL (a - NPD) embodied the balance of spectra and had a possibility of getting white emission. In a device with 0.3 nm a-NPD, it had a maximum power efficiency of 3.80 lm/w at 250 $cd/m^2$, a luminance of 1200 $cd/m^2$ at 100 $mA/cm^2$ , and the CIE coordinates were (0.353, 0.357).

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
• /
• pp.944-947
• /
• 2003

We report efficient white organic electroluminescent devices consisting of a blue-emitting layer of 9,10-bis[(2",7"-di-t-butyl)-9',9"-spirobifluorenyl]anthracene (TBSA) and a red-emitting layer of 4-dicyanomethylene-2-methyl-6-[2-(2,3,6,7-tetrahydro-1H,5H-benzo[i,j]quinolizin-8-yl)vinyl]-4H-pyran) (DCM2) doped into 4,4'bis[N-(1-napthyl)-N-phenyl-amino]-biphenyl (${\alpha}-NPD$). The device shows the CIE coordinates of (0.32, 0.37). The external quantum efficiency is about 3.4 % and the luminous efficiency is about 3.9 lm/W at luminance of 100 $cd/m^{2}$. The maximum luminance is about 45,400 $cd/m^{2}$ at 11.5 V.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 제39회 하계학술대회
• /
• pp.1448-1449
• /
• 2008

Inkjet printing is commonly used in depositing the solution of functional materials on the specific locations of a substrate, and also it can provide easy and fast patterning of polymer films over a large area. Inkjet printing is applicable to fabricating an organic light emitting diode (OLED), since conducting materials used as emissive electroluminescent layers can be manufactured into inks for ink jetting. By using the inkjet technology, we have succeeded in patterning a poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) layer and a poly[2-Methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) layer on the Indume tin oxide (ITO) patterned substrates, and fabricating organic light emitting diodes.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
• /
• pp.94-97
• /
• 2002

We report highly efficient phosphorescent-dye-doped polymeric light-emitting devices. The devices consist of a polymeric light-emitting layer comprising the phosphorescent dye, host, and matrix polymers. We patterned the phosphorescent-dye-doped polymeric layer with the LITI technique. The devices showed high efficiencies and good pattern quality to adapt to the development of full-color electroluminescent (EL) devices.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
• /
• pp.1476-1478
• /
• 2009

The characteristics of polymer inkjet printing were investigated systematically in this paper. PEDOT/PSS as a hole injection layer and MEH-PPV as a light emitting layer were used for inkjet printing experiment. Inkjet head controlling technology and surface modification technology were also applied for polymer inkjet printing. With the developed polymer inkjet printing technology, OLED(Organic Light Emitting Display) was successfully fabricated and demonstrated.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
• /
• pp.758-761
• /
• 2009

The electroluminescent devices with the phenylnaphthyldiamine HTMs as the hole-transporting layer were more efficient than that with the biphenyldiamine HTM 1. Particularly, the life-time of the device IV using HTM 2 is about two times longer than that of the reference device III with HTM 1 within the measured current density, indicating more effective recombination at the emitting layer of device IV.

• Journal of Information Display
• /
• 제8권3호
• /
• pp.11-16
• /
• 2007

Theoretical simulations of spatial distribution of charge carriers and recombination rate, and J-V characteristics of the multi-layer organic light emitting diodes are carried out. Drift-diffusion current transport, field-dependent carrier mobility, exponential and Gaussian trap distribution, and Langevin recombination models are included in this computer model. The simulated results show good agreement with the experimental data confirming the validity of the physical models for organic light emitting diodes.

• Transactions on Electrical and Electronic Materials
• /
• 제5권1호
• /
• pp.24-28
• /
• 2004

We have used ITO/Alq$_3$/Al structure to study electrical conduction mechanism in organic light-emitting diodes. Current-voltage-luminance characteristics were measured at room temperature by varying the thickness of Alq$_3$ layer from 60 to 400mm. We were able to confirm that there are three different mechanisms depending on the applied voltage region; ohmic, space-charge-limited current, and trap-charge-limit-current mechanism. And the maximum luminous efficiency was obtained when the thickness of Alq$_3$ layer is 200nm.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
• /
• pp.374-374
• /
• 2012

Nowadays, Active Matrix Organic Light-Emitting Diodes (AM-OLEDs) are the superior display device due to their vivid full color, perfect video capability, light weight, low driving power, and potential flexibility. One of the advantages of AM-OLED over Liquid Crystal Display (LCD) lies in its flexibility. The potential flexibility of AM-OLED is not fully explored due to its sensitivity to moisture and oxygen which are readily present in atmosphere, and there are no flexible encapsulation layers available to protect these. Therefore, we come up with a new concept of Inorganic-Organic hybrid thin film as the encapsulation layer. Our Inorganic layer is Al2O3 and Organic layer is F-Alucone. We deposited these layers in vacuum state using Atomic Layer Deposition (ALD) and Molecular Layer Deposition (MLD) techniques. We found the results are comparable to commercial requirement of 10-6 g/m2 day for Water Vapor Transmission Rate (WVTR). Using ALD and MLD, we can control the exact thin film thickness and fabricate more dense films than chemical or physical vapor deposition methods. Moreover, this hybrid encapsulation layer potentially has both the flexibility of organic layers and superior protection properties of inorganic layer.

• 전기학회논문지
• /
• 제59권5호
• /
• pp.918-921
• /
• 2010

We have proposed an dielectric layer to improve the luminance of red organic light emitting device. Here, we have calculated refractive index of dielectric layer material that was revised refractive index of organic material, ITO and glass. Refractive index of dielectric layer material was 1.711. The structure of dielectric layer was designed in organic material/ITO/dielectric layer/glass. Dielectric material changed thickness that deposited by ion-assisted deposition system. Transmittances of ITO were 95.66-98.85 [%]. Red OLED was fabricated with the structure of TPD($400[{\AA}]$)/DCMII($20[{\AA}]$), Rubrene($20[{\AA}]$)/Alq3($500[{\AA}]$)/LiF($15[{\AA}]$)/Al($1,000[{\AA}]$). Turn-on voltage and Luminance of Red OLED were 10 [V] and 5,857 cd/m2.