• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.928-931
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• 2003

In order to realize full color display, two approaches were used. The first method is the patterning of red, green, and blue emitters using a selective deposition. Another approach is based on a white-emitting diode, from which the three primary colors could be obtained by micro-patterned color filters. White-light-emitting organic light emitting devices (OLEDs) are attracting much attention recently due to potential applications such as backlights in liquid crystal displays (LCDs) or other illumination purposes. In order for the white OLEDs to be used as backlights in LCDs, the light emission should be bright and have Commission Internationale d'Eclairage (CIE) chromaticity coordinates of (0.33, 0.33). For obtaining white emission from OLEDs, different colours should be mixed with proper balances even though there are a few different methods for mixing colors. In this study, we will report a white organic electroluminescent device using exciton diffusion length concept.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.497-499
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• 2005

A portable terminal assistant market grows rapidly every year and it requires many change in research on display devices. Among many newly developing methods, OLED(Organic Light Emitting Diode) is considered an advanced flat display device because its excellent characteristics, including high speed response, full color performance, low power consumption and flux of panel. However changes in the market of display shows that the market will require 3-dimensional images, but it is hard for existing 2-dimensional displays to make 3-dimensional images. Therefore we will try to find various methods such as holograms. In this paper, we will show existing flat displays can make 3-dimensional images by applying Lenticular Screen printing techniques on the organic semiconductor display device.

• Journal of Industrial and Engineering Chemistry
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• 제68권
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• pp.350-354
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• 2018

Lifetime study of blue phosphorescent and thermally activated delayed fluorescent organic light-emitting diodes was carried out to understand the dominant degradation process during electrical operation of the devices. Doping concentration dependence of the phosphorescent and thermally activated delayed fluorescent organic light-emitting diodes was studied, which demonstrated long lifetime at low doping concentration in the phosphorescent devices and at high doping concentration in the thermally activated delayed fluorescent devices. Detailed mechanism study of the two devices described that triplet-triplet annihilation is the main degradation process of phosphorescent organic light-emitting diodes, whereas triplet-polaron annihilation is the key degradation factor of the thermally activated delayed fluorescent devices.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.156-156
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• 2010

We have developed highly efficient blue phosphorescent organic light-emitting devices (OLED) with simplified architectures using blue phosphorescent material. The basis device structure of the blue PHOLED was anode / emitting layer (EML) / electron transport layer (ETL) / cathode. The dopant was partially doped into the host layer for investigating recombination zone, current efficiency, and emission characteristics of the blue PHOLEDs.

• Applied Science and Convergence Technology
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• 제25권1호
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• pp.1-6
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• 2016

Quantum dots (QDs) are considered as excellent color conversion and self-emitting materials for display and lighting applications. In this article, various technologies which can be used to realize white light emission with QDs are discussed. QDs have good color purity with a narrow emission spectrum and tunable optical properties with size control capabilities. For white light emission with a color-conversion approach, QDs are combined with blue-emitting inorganic and organic light-emitting diodes (LED) to generate white emission with high energy conversion efficiency and a high color rendering index for various display and lighting applications. Various device structures for self-emitting white QD light-emitting diodes (QD-LED) are also reviewed. Various stacking and patterning technologies are discussed in relation to QD-LED devices.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
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• pp.25-28
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• 2002

We have been fabricated white organic light emitting diode with two-wavelength ard mixing blue emit in DPVBi (4, 4-bis(2, 2-diphenylvinyl)-1, 1 -biphenyl)layer and yellow emit in rubrene (5, 6, 11, 12-tetraphenylnaphthacene)as emitting layer which are controlled with thickness. This device emits white light emitting in CIE (0.29, 0.33), 1000cd/$m^2$ at DC 18V.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.773-776
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• 2002

Efficient organic white light-emitting diodes are fabricated by doping [bis(2-methyl-8-quinolinolato) (tripheny-siloxy)aluminium (III)] (SAlq), a blue-emitting layer, with a red fluorescent dye of 4-dicyanomethylene-2-methyl-6-{2-(2,3,6,7-tetrahydro-1H,5H-benzo[i,j]quinolizin-8-yl)vinyl}-4H-pyran (DCM2). The incomplete energy transfer from blue-emitting SAlq to red-emitting DCM2 enables to obtain a balanced white light-emission. A device with the structure of ITO/TPD (50 nm)/SAlq:DCM2 (30 nm, 0.5 %)/$Alq_3$ (20 nm)/LiF (0.5 nm)/AI shows emission peaks at 456 nm and 482 nm from SAlq and at 570 nm from DCM2. The white light-emitting device shows an external quantum efficiency of about 2.3 %, a luminous efficiency of about 2.4 lm/W, and the CIE chromaticity coordinates of (0.32, 0.37) at 100 cd/m^2. A maximum luminance of about 23,800 cd/m^2. is obtained at 15 V and the current density of 782 mA/cm^2.

• Journal of Information Display
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• 제4권2호
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• pp.13-18
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• 2003

We synthesized bis (2-methyl-8-quinolinolato)(triphenylsiloxy) aluminum (III) (SAlq), a blue-emitting material having a high luminous efficiency, through a homogeneous-phase reaction. The photoluminescence (PL) and electroluminescence (EL) spectra of SAlq show two peaks at 454 nm and 477 nm. Efficient white light-emitting devices are fabricated by doping SAlq with a red fluorescent dye of 4-dicyanomethylene-2-methyl-6-{2-(2,3,6,7-tetrahydro-1H,5H-benzo[i,j]quinolizin-8yl) vinyl}-4H-pyran (DCM2). The incomplete energy transfer from blue-emitting SAlq to red-emitting DCM2 results in light-emission of both blue and orange colors. Devices with the structure of ITO/TPD (50 nm)/SAlq:DCM2 (30 nm, 0.5 %)/$Alq_3$ (20 nm)/LiF (0.5 nmj/Al show EL peaks at 456 nm and 482 nm originating from SAlq and at 570 nm from DCM2, resulting in the Commission Internationale d'Eclairage (CIE) chromaticity coordinates of (0.32, 0.37). The device exhibits an external quantum efficiency of about 2.3 % and a luminous efficiency of about 2.41m/W at 100 $cd/m^2$. A maximum luminance of about 23,800 $cd/m^2$ is obtained at the bias voltage of 15 V.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.331-334
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• 2000

The organic electroluminescent(EL) device has gathered much interest because of its large potential in materials and simple device fabrication. We fabricated EL devices which have a blended single emitting layer containg poly(Nvinylcarbazole)[PVK] and poly(3-dodecylthiophene)[P3DoDT]. The molar ratio between P3DoDT and PVK changed with 1:0, 2:1 and 1:1. To improve the external quantum efficiency of EL devices, we applied insulating layer, LiF layer between polymer emitting layer and AI electrode. All of the devices emit orange-red light and it's can be explained that the energy transfer occurs from PVK to P3DoDT. Within the molar ratio 1:0, 2:1 and 1:1, the energy transfer was not saturated, which results in the not appearance of PVK emission in the blue region. In the voltage-current and voltage-light power characteristics of devices applied LiF layer, current and light power drastically increased with increasing with applied voltage. In the consequence of the result, the light power of the device have a molar ratio 1:1 with LiF layer was about 10 times larger than that of the device without PVK at 6V.

• 한국전기전자재료학회논문지
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• 제17권2호
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• pp.217-222
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• 2004

The white-light-emitting organic LED(OLED) with two-wavelength was fabricated using the DPVBi of blue emitting material and a series of orange color fluorescent dye(Rubrene) by vacuum evaporation processes. The basic structure of white-light-emitting OLED was ITO/NPB(150$\AA$)/DPVBi/Rubrene/BCP(100$\AA$)/Alq$_3$(150$\AA$)/Al(600$\AA$). We analyzed the fabricated device through the changes of the DPVBi and Rubrene layer's thickness. We obtained the white-light-emitting OLED with white color light and the CIE coordinate of the device was (0.29, 0.33) at applied voltage of 13V when the thickness of DPVBi layer was 210$\AA$ and the thickness of Rubrene layer was 180$\AA$. At a current of 100㎃/$\textrm{cm}^2$, the quantum efficiency was 0.35％ and at a voltage of 20V, it was 0.405％.