• 제목/요약/키워드: Light-emitting diodes

검색결과 1,318건 처리시간 0.032초

Synthesis and properties of organic light-emitting diodes using BECCIP material

  • Lee, Ho-Sik;Kim, Sang-Keol;Lee, Won-Jae;Park, Jong-Wook;Song, Min-Jong;Kim, Tae-Wan;Kang, Dou-Yol
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 추계학술대회 논문집
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    • pp.174-176
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    • 2000
  • We have synthesized the new blue electroluminescent material, Bis(3-N-ethylcarbazolyl)cyanoisophthalidene(BECCIP), and characterized its properties by UV/visible absorption, photoluminescent(PL) and electroluminecent(EL) spectrum. This material is well vacuum-deposited far thin film and has clear surfaced thin film property. The BECCIP shows blue PL and EL spectra at around at 485nm.

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온도 변화에 따른 유기 전기 발광 소자의 전기적 특성 (Temperature-dependent current-voltage characteristics of Organic Light-Emitting Diodes(OLEDs))

  • 이호식;정택균;김상걸;정동회;장경욱;이원재;김태완;이준웅;강도열
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2001년도 추계학술대회 논문집
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    • pp.370-373
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    • 2001
  • Temperature-dependent current-voltage characteristics of Organic Light-Emitting Diodes (OLEDs) were studied. The OLEDs were based on the molecular compounds, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-diphenyl-4,4'-diamine (TPD) as a hole transport and trois(8-hydroxyquinoline) aluminum(Alq$_3$) as an electron transport and emissive material. The current-voltage characteristics were measured in the temperature range of 10[K] and 300[K]. A conduction mechanism in OLEDs was interpreted in terms of tunneling and trap-filled limited current.

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정공 주입 물질 두께 변화에 따른 유기 발광 다이오우드 효율 향상 (Efficiency Improvement of the Organic Light-Emitting Diodes depending on Thickness Variation of Hole-Infection Materials)

  • 김원종;이영환;차기호;이상교;김태완;홍진웅
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년도 제37회 하계학술대회 논문집 C
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    • pp.1291-1292
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    • 2006
  • In the structure of ITO/HIL/$Alq_3$/Al device, we investigated an efficiency improvement of the Organic Light-Emitting Diodes depending on thickness variation of hole-injection layer. Using the thermal evaporation in a base vacuum $5{\times}10^{-5}$[Torr], we have measured efficiency after the $Alq_3$ was evaporated to 100 [nm] as a deposition rate $1.5[{\AA}/s]$. In optimal condition, when PTFE thickness increased from 0 to 3.0 [nm], we have obtained that an optimal thickness of PTFE was 2.5 [nm]. And using the PTFE, luminance efficiency and external quantum efficiency of the device were improved by 12.8 times and 11.1 times, respectively.

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NiO/AZO anode를 적용한 OLED의 정공주입 향상에 관한 연구 (A study on the enhancement of hole injection in OLED using NiO/AZO Anode)

  • 진은미;송민종;김진사;박춘배
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.444-445
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    • 2007
  • Aluminum-doped zinc oxide (AZO) films are attractive materials as transparent conductive electrode because they are inexpensive, nontoxic and abundant element compared with indium tin oxide (ITO). AZO films have been deposited on glass (coming 1737) substrates by RF magnetron sputtering system. An ultrathin layer of nickel oxide (NiO) was deposited on the AZO anode to enhance the hole injections in organic light-emitting diodes (OLED). The current density-voltage and luminescence-voltage properties of devices were studied and compared with ITO device.

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ITO/$Alq_3$/Al 구조 박막의 유전분산과 흡수에 관한 연구 (A Study on the Dielectric Dispersion and Absorption of ITO/$Alq_3$/Al Thin Film)

  • 오용철;김상진;성낙진
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.490-491
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    • 2007
  • We have investigated dielectric dispersion and absorption in organic light-emitting diodes using 8-hydroxyquinoline aluminum($Alq_3$) as an electron transport and emissive material. We analyzed the dielectric dispersion and absorption of organic light emitting diodes using impedance characteristics measurement by the auto-balancing bridge technique of ITO/$Alq_3$/Al. Impedance characteristics was measured complex impedance Z and phase e in the frequency range of 40Hz to $10^8Hz$. We obtained dielectric constant and loss tangent (tan $\delta$) of the device. From these analyses, we are able to interpret a dielectric dispersion and dielectric absorption contributed by an interfacial and orientational polarization.

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DC 스퍼터링 증착에 의한 AI 전극을 갖는 전계발광소자 제작 (Fabrication of the Electroluminescence Devices with Al electrode deposited by DC sputtering)

  • 윤석범
    • 한국전기전자재료학회논문지
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    • 제13권5호
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    • pp.376-382
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    • 2000
  • We successfully fabricated OLED(Organic Light Emitting Diodes) with Al cathodes electrode deposited by the DC magnetron sputtering. The effects of a controlled Al cathode layer of an Indium Tin Oxide (ITO)/blended single polymer layer (PVK Bu:PBD:dye)/Al light emitting diodes are described. The PVK (Poly(N-vinylcarbazole)) and Bu-PBD (2-(4-biphenyl-phenyl)-1,3,4-oxadiazole) are used hole transport polymer and electron transport molecule respectively. We found that both current injection and electroluminescence output are significantly different with a variable DC sputtering power. The difference is believed to be due to the influence near the blended polymer layer/cathode interface that results from the DC power and H$\sub$2//O in a chamber. And DC sputtering deposition is an effective way to fabricate Al electrodes with pronounced orientational characteristics without damage occurring to metal-organic interface during the sputtering deposition.

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$ITO/Alq_3(60nm)/Al$의 유기 발광 소자에서 바이어스 전압과 주파수에 따른 전기적 특성 (Voltage and frequency dependent electrical properties in organic light-emitting diodes of $ITO/Alq_3/Al$)

  • 정동회;오현석;허성우;이원재;송민종;이준웅;김태완
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.464-468
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    • 2003
  • Complex impedances with frequency and voltage variation were analyzed in $ITO/Alq_3(60nm)/Al$ device structure. At low frequency, complex impedance is mostly expressed by resistive component, and at the high frequency by resistance and capacitive component. We have also evaluated resistance, capacitance and permittivity.

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마이크로파 근접장 현미경을 이용한 유기 발광소자내 dark spot 연구 (Investigation of dark spots in organic light emitting diodes by using a near-field scanning microwave microscope)

  • 윤순일;유현준;박미화;김송희;이기진
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.494-497
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    • 2003
  • We report the dark spots in organic light emitting diodes by using a near-field scanning microwave microscope. Devices structure was glass / indium-tin-oxide(ITO) / copper-pthalocyiane(Cu-Pc) / tris-(8-hydroquinoline)aluminum(Alq3) / aluminum(Al). We made artificial dark spots by using a etching technique on a ITO substrate. Near-field scanning microwave microscope images and reflective coefficient of dark spots were measured and compared by the change of various applied voltage changes 0-15V.

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TPD/$Alq_3$를 이용한 유기 발광 소자의 온도에 따른 전압-전류 특성 (Temperature Dependent Current-Voltage Characteristics of Organic Light-Emitting Diodes using TPD/$Alq_3$)

  • 한원근
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.533-534
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    • 2005
  • Temperature-dependent current-voltage characteristics of organic light-emitting diodes(OLEDs) were studied in a device structure of ITO/TPD/$Alq_3$/Al. The OLEDs were based on the molecular compounds, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-l,1'-diphenyl-4,4'-diamine(TPD) as a hole transport and tris(8-hydroxyquinoline) aluminum($Alq_3$) as an electron transport and emissive material. The current-voltage characteristics were measured in the temperature range of 10K and 300K. We analyzed an electrical conduction mechanism of the OLEDs using space-charge-limited current(SCLC) and Fowler-Nordheim tunneling.

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임피던스 분석법을 이용한 유기발광 다이오드의 전기적 특성 분석 (Electrical property analysis of Organic Light Emitting Diodes using impedance spectroscopy)

  • 박재일;박형준;남은경;정동근;이준신
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.452-453
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    • 2007
  • In this work, enhanced simulation is proposed by using impedance spectroscopy. The impedance spectroscopy is one of the popular methods to measure the electrical property of Organic Light Emitting Diodes. The results show that the equivalent circuit needs a inductance element linked by serial connection and the element of resistance is more important role to decide the electrical property.

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