• 한국응용과학기술학회지
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• 제14권2호
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• pp.81-85
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• 1997

Tris(8-hydroxyquinoline)-aluminum complex($AlQ_3$) having greenish luminescent characteristics was synthesized and it was confirmed with UV-Vis absorption spectroscopy, elemental analysis, and FT-IR spectroscopy that $AlQ_3$ was successfully synthesized. Thin films of $AlQ_3$ having multilayer structure were prepared by spin coating method and vacuum evaporation technique. Photopluminescent characteristics of these films were investigated by Luminescence spectroscopy and Current-Voltage(I-V) characteristics of these films were also investigated.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권7호
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• pp.322-327
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• 2002

Temperature-dependent current-voltage characteristics of organic light-emitting diodes(OLEDs) were studied in a device structure of ITO/TPD/Alq$_3$/Al to understand conduction mechanism. The current-voltage characteristics were measured in the temperature range of 8K ~ 300K. We analyzed an electrical conduction mechanism of the OLEDS using space-charge-limited current(SCLC) and Fowler-Nordheim tunneling. In the temperature range above 150k, the conduction mechanism could be explained by space charge limited current from the inversely proportional temperature dependence of exponent m. The characteristic trap energy is found to be about 0.15ev. At low temperatures below 150k, the Fowler-Nordheim tunneling conduction mechanism is dominant. We have obtained a zero field barrier height to be about 0.6~0.8eV.

• 한국전기전자재료학회논문지
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• 제18권11호
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• pp.1038-1042
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• 2005

We have investigated dielectric properties depending on bias voltage in organic light-emitting diodes using 8-hydroxyquinoline aluminum $(Alq_3)$ as an electron transport and emissive material. We analyzed the dielectric properties of organic light-emitting diodes using impedance of characteristics. Impedance characteristics was measured complex impedance Z and phase $\theta$ in the frequency range of 40 Hz to $10^8$ Hz. We obtained complex electrical conductivity, dielectric constant, and loss tangent $(tan\delta)$ of the device at room temperature. From these analyses, we are able to interpret a conduction mechanism and dielectric properties contributed by an interfacial and orientational polarization.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 C
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• pp.443-445
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• 2000

The high mobilitie sallow larger current to be reached under operation in the space charge limited conduction region, hence facilitate access to higher luminance as required for passive matrix panel. In this work, we have investigated the molecular alignment control effect of organic electroluminescent devices. we aligned the p-sexiphenyl(6p) using a simple rubbing treatment. We studied the anisotropic optical properties and electrical characteristics.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.506-509
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• 2002

In this paper. we give pressure stimulation into organic ultra thin films and detected the induced displacement current proper ties, and then manufacture a device under the accumulation condition. In processing of a device manufacture. And electroluminescence(EL) from conjugated polymers has recently received great attention because polymer light-emitting diodes(LEDs) clealy have potential for applications such as large-area displays. The operation of polymer LEDs is based on double injection of electrons and holes from the elextrodes. followed by formation of excitons whose radiative decay results in light emission at wavelength characteristic to the material. In this paper, we fabricated the single layer EL device using $Alq_3$ as emitting material. According as turn on voltage could know about 5.5V in voltage-current characteristics and voltage rise, current could see that increase as non-linear, Current and ruminance can see that express similar relativity in voltage, and could know that ruminance is expressing current relativity.

• 한국전기전자재료학회논문지
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• 제14권9호
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• pp.762-767
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• 2001

We report the white light emission from the multilayer organic electroluminescent(EL) device using exciplex emission. The exciplex at 500nm originated between poly(N-vinylcarvazole)(PVK) and 2,5-bis(5'-tert-butyl-2-benzoxazoly)thiophene(BBOT) and exciplex of 50nm originated from N,N'-diphenyl-N,N'-(3-methyphenyl)-1,1'-biphenyl-4,4'-diamine(TPD) and BBOT were observed. Also, the energy transfer from PVK to BBOT and poly(3-hexylthiophene)(P3HT) in mixed emitting materials was occurred. The electroluminescence(EL) spectra of organic EL device which have a device structure of ITO/CuPc(5nm)/emitting layer(100nm)/BBOT(30nm)/LiF(1.4nm)/Al(200nm) were slightly changed as a function of the applied voltage. The luminance fo 12.3 ${\mu}$W/$\textrm{cm}^2$ was achieved at 20V and EL spectrum measured at 20V corresponds to Commission Internationale de L\`Eclairage(CIE) coordinates of x=0.29 and y=0.353.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.253-257
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• 1998

Organic-based electroluminescent devices have attracted lots of interests because of their possible application as large-area flat pan디 display. In this study, current-voltage (I-V) characteristics of MEH-PPV thin films was investigated using various metal as a top electrode, where MEH-PPV thin films were prepared on 170 substrate by spin coating method and various metal such as Al, Ag, In, MgIn was deposited on MEH-PPV thin films as a top electrode.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 전문대학교육위원
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• pp.82-85
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• 2005

Organic EL has been expected to adopt to a new styles of technology that make flat display after Tang & Vanslyke made good electric luminescence device in late 1980s. Their studies based on multi layer structure that consists of emitting layer and carrier transporting layer using proper organic material. In this study, we made multi layer device using $Eu(TTA)_3(phen)$ as a luminescence material by PVD and investigate luminous properties of each device. But oxidization of organic layer by ITO, energy walls in both pole interface, contaminations of ITO surface, importance of protecting membrane, diffusive dimming of light to cathode organic layer, these causes of degradations are common facts of a macromolecule and micromolecule. We think these degradation caused by the impact of heat and electro-chemical factor, bulk effect and interface phenomenon, and raise a question.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.103-106
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• 1999

Organic electroluminescent devices (OELDs) have received a great deal of attention due to their potential application as full-color displays. Europium complexes are known as excellent red light-emitting materials for OELDs since they show intense photoluminescence at around 612 nm with a narrow spectral bandwidth. In this study, a novel curopium complex, Eu(TTA)$_3$(TPPO) was synthcsizcd and its photoluminescent and electroluminescent characteristics were investigated with a device structure of ITO/TPD/Eu(TTA)3(TPPO)/A1q$_{3}$ Al, where sharp emission at the wavelength of 615 nm has been observed. Details on the electrical properties of these structures will be also discussed.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.316-319
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• 2001

Organic light emitting diodes(OLEDs) with a hole injection layer inserted between Indium-Tin-Oxide(ITO) anode and hole transport layer were fabricated. The effect of plasma treatment on the surface properties of Indium-Tin-Oxide(ITO) anode were studied. The electrical and optical characteristics of the fabricated organic light emitting diodes(OLEDs) were also studied. The diode including of plasma treated ITO substrate and the hole injection layer, which showed the luminance of 5280 cd/㎡ at 8 V