• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.5
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• pp.429-434
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• 2002

In this paper, multiheterostructure white organic light-emitting device was fabricated by vacuum evaporation. The structure of white organic light-emitting device is ITO/CuPc/TPD/DPBi:DPA/$Alq_3/Alq_3$:DCJTB/BCT/$Alq_3$/Ca/Al. Three primary colors are implemented with DPVBi, Alq$_3$and DCJTB. The maximum EL wavelength of the fabricated white organic light-emitting device is 647nm. And the CIE coordinate is (0.33, 0.33) at 13 V. In the fabrication of white organic light-emitting devices with DCJTB, $Alq_3$, DPVBi, the EL spectrum has two peaks at 492nm, 647nm. Two peaks appeared because the blue light is combined with green light. The maximum wavelength of red light is not changed with applied voltage. After voltage applied, for the first time, the electrons met the holes in the red emission layer and emitted red light. And then the electrons moved to the green emission layer, and blue emission layer continuously. Finally, when all of the emission layer activated, the white light is emitted.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1291-1292
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• 2008

ITO is widely used as an anode material in OLED, because of its good transparency, low electrical resistivity, high work function, and efficient hole injection properties. The interface between the electrode and the organic layer in the OLED effects the charge injection process and may influence the electrical and the luminance properties. Surface treatment of ITO, such as an Aquaregia treatment has been shown to enhance the efficiency, and luminance characteristics of the OLED. In this study, we investigated the effect of Aquaregia treatment. The fundamental structures of the OLED were ITO/NPB/$Alq_3$/LiF/Al. The current density-voltage-luminance, efficiency, and lifetime characteristics were measured with untreated and Aquaregia-treated ITO substrates. The Aquaregia treatment was found to enhance the performance of OLED. For the Aquaregia treated device, the maximum luminance and efficiency were increased by about 2 times compared to the untreated device. The mechanism of the Aquaregia treatment is discussed based on AFM analyses.

• Journal of the Korean Society of Clothing and Textiles
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• v.35 no.10
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• pp.1188-1198
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• 2011

This study proposes the use of firework shapes to design fashion accessories in the judgment that they are appropriate for the expression of creative images in consideration of the display of fireworks as a kind of entertainment and a festive symbol. This study promotes the sustainable application of firework shapes to develop the designs of fashion culture items that feature a distinctive personality and uniqueness. In this present study, the proposed fashion accessory design was intended to create an entertaining new atmosphere that uses an Organic Light Emitting Diode (OLED) that draws attention as a futuristic display. In terms of methodology, a literature review of firework shapes and OLED was conducted; in addition, Adobe Illustrator CS2 and Adobe Photoshop CS2 were used to develop six different standard motive designs with formative design elements represented by a variety of firework shapes. Each of the six motifs was further expanded with different color combinations. Rich images are produced with the use of pink, blue, purple, green, yellow, orange, and red, in conjunction with various OLED effects to express the three-dimensional images of fireworks. The motifs are applied to three types of items: bags, bracelets, and necklaces. For the video images, evening and tote bags, pendants, and bangles were used. Shifting images and lights should produce unique images as well as satisfy the consumer desire for entertainment. The Adobe Image Ready software was used to present the motive of fireworks applied to the design of fashion accessories in video images but not in still-cut images due to physical constraints of this paper.

• Journal of the Semiconductor & Display Technology
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• v.16 no.1
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• pp.40-44
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• 2017

The effect of weak dielectric silicone dioxide($SiO_2$) embedded in polyfluorene(PFO) emitting layer of polymer-based multi structure OLED was investigated. Indium tin oxide(ITO)/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS)/poly(9,9-di-n-octylfluorenyl-2,7-diyl)(PFO)/2,2,2"-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi)/aluminum(Al) structure OLED was fabricated by spin-coating method. Applied electric field causes some effect on $SiO_2$ in PFO layer. Thus, interaction between polymers and affected $SiO_2$ might generate electrical and luminance properties change. Experimental results, show the reduced threshold voltage of 6 V(from 23 V to 17 V). The maximum current density was rather increased from $71A/m^2$ to $610A/m^2$ and maximum brightness was also increased from $7.19cd/m^2$ to $41.03cd/m^2$, 9 and 6 times each. Additionally we obtained colour broadening result due to the increasing of blue-green band emission. Consequently we observed that electrical and luminance properties are enhanced by adding $SiO_2$ and identified the possibility of controlling the emission colour of OLED device according to colour broadening.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.307-308
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• 2009

We have proposed an index matching film to improve the emitting efficiency of green OLED. Here, SiO2 and TiO2 were selected to coat the green OLED. The structures of index matching film were designed in G1ass/TiO2/SiO2/ITO and SiO2/TiO2/Glass/ITO. Then, these materials were deposited by ion-assisted deposition system. Transmittances of deposited devices were 86.14 and 85.07 %, respectively.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.465-468
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• 2008

New green light emitting phosphorescent devices with host structure of TCTA[4,4',4"-tris(N-carbazolyl)-triphenylamine]/$TCTA_{0.5}TPBi_{0.5}$/TPBI[1,3,5-tris(N-phenylbenzimiazole-2-yl)benzene] were proposed and investigated according to the thickness combination of host layers and the doping level of $Ir(ppy)_3$[tris(2-phenylpyridine) iridium(III)].

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.820-822
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• 2009

Tandem white organic light emitting diodes (WOLEDs) are fabricated by using a transparent interconnecting layer of Al:LiF composite/molybdenum oxides ($MoO_3$). We demonstrate two types of tandem WOLEDs consisting of two color emissions (red and blue emission) and three color emissions (red, green and blue emission). Tandem WOLED consisting of three color emission shows higher external quantum efficiency and current efficiency.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.272-276
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• 2004

Great strides in organic light emitting device (OLED) technology have resulted in a number of commercial products. To continue this growth into large area displays, for example televisions, an understanding of the mechanisms that drive the OLED device efficiency and lifetime performance is critical. In this work, we consider maximizing the efficiency lifetime product based on phosphorescent OLED ($PHOLED^{TM}$) technology. We report green PHOLEDs with luminous efficiency of 82 cd/A, 5.7 V and 10,000 hours lifetime at 1,000 cd/$m^2$,red PHOLEDs with CIE of (0.67,0.33), 11 cd/A and 35,000 hours lifetime at 500 cd/$m^2$ and recent progress in blue demonstrating efficiencies of 18 cd/A at 200 cd/$m^2$.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1120-1123
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• 2008

Efficient, color stable multi-EML WOLED have been fabricated using newly synthesized yellowish green dopant Ir(chpy)3 or Ir(mchpy)3. The devices have high external quantum efficiency of 11.7%, color rendering index of 87, variation of CIE coordinate of (0.02, 0.01) between 10 to 5000 cd/m2, and low roll-off in efficiency with increasing brightness.

• 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.