• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.263-266
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• 1999

Electrolunlinescent devices based on conjugated polymer emitting materials have been much attracted possible applications for multicolor flat panel display, since the conjugated polymers have a small band gap emitting obtained at a low driving voltage. In this paper, we fabricated the single layer EL device using poly(3-hexylthiophene) as emitting material Electroluminescence(EL) and I-V-L characteristics of indium-tin-oxide[ITO]P3HT/AI device with a various thickness were investigated. It was demonstrate that the I-V characteristics depend, not the voltage but the electric- field strength, The current is dependent on the electric filed and not on the applied voltage, indicating that the carriers are injected by a tunneling process. In the device, the barrier to hole injection is only 0.5eV and the barrier to electron injection is 1.5eV.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 광주전남지부
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• pp.114-118
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• 2006

We investigated the transient electroluminescence (EL) and modulation characteristics of red organic light-emitting diodes (OLEDs), which consist with 4-(dicyanomethylene)-2-i -propyl-6-(1,1,7,7-tetramethyljulolidyl-9-cnyl)-4H-pyran (DCJTI) and rubrene doped into tris(8-hydroxyquinoline)aluminum ($Alq_3$). The transient EL waveforms showed two components, the overshooting peak and constant component, indicating that the excess amount of accumulated charges simultaneously recombine at the onset moment. This overshooting effect reduced the rise time of transient EL and enhanced the optical output of OLEDs when the pulse voltage applied to the device. We demonstrated that the red OLEDs could be use for the high-speed switching application by driving at more than 100 MHz and transmitting the video signals utilized as the electro-optical conversion device

• 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.

• 센서학회지
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• 제6권4호
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• pp.252-257
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• 1997

ITO(indium-tin-oxide)/PPV(poly(p-phenylenevihylene))/음극 전극의 단층구조와 ITO /PVK(poly(N-vinylcarbazole))/PPV/음극전극의 이층구조를 가진 유기 EL(electroluminescence) 소자를 제작하였으며, 전기-광학적 특성을 측정하였다. 실험 결과, 단층구조에서는 PPV막의 열변환 온도를 $140^{\circ}C$에서 $260^{\circ}C$로 증가할수록 최대 휘도가 $118.8\;cd/m^{2}$(20V)에서 $21.14\;cd/m^{2}$(28V)으로 감소하였고, EL 스펙트럼의 최대 피크가 500nm에서 580nm로 이동하였다. 또한, 음극전극의 일함수가 낮을수록 소자의 발광휘도와 주입 전류는 증가되었다. 이층구조에서는 PVK막의 농도가 감소함에 따라 발광휘도가 $70.71\;cd/m^{2}$(32V)에서 $152.7\;cd/m^{2}$(26V)으로 증가하였다.

• 한국전기전자재료학회논문지
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• 제13권5호
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• pp.437-443
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• 2000

In this study several lanthanide complexes such as Eu(TTA)$_3$(Phen), Tb(ACAC)$_3$-(Cl-Phen) were synthesized and the white-light electroluminescence(EL) characteristics of their thin films were investigated where the devices having structures of anode/TPD/Tb(ACAC)$_3$(Cl-Phen)/Eu(TTA)$_3$(Phen)/Alq$_3$or Bebq$_2$/cathode and the low work function metal alloy such as Li:Al was used as the electron injecting electrode(cathode). Device structure of glass substrate/ITO/TPD(30nm)/Tb(ACAC)$_3$(Phen)(30nm)/Eu(TTA)$_3$(Phen)(6nm)/DCM doped Alq$_3$(10nm)/Alq$_3$(20nm)/Li:Al(100nm) was also fabricated and their EL characteristics were investigated where Eu(TTA)$_3$(Phen) and DCM doped Alq$_3$were used as red light-emitting materials. It was found that the turn-on voltage of the device with non-doped Alq$_3$was lower than that of the devices with doped Alq$_3$and the blue and red light emission peaks due to TPD and Eu(TTA)$_3$(Phen) with non-doped Alq$_3$were lower than those with DCM doped Alq$_3$Details on the white-light-emitting characteristics of these device structures were explained by the energy and diagrams of various materials used in these structure where the energy levels of new materials such as ionization potential(IP) and electron affinity(EA) were measured by cyclic voltametric method.

• 폴리머
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• 제28권5호
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• pp.367-373
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• 2004

발광체로 페릴렌기와 전자 전달체로 트리아진기를 측쇄로 가지는 새로운 비공액계 청색 발광 공중 합체를 합성하였다. 제조한 공중합체는 클로로벤젠, THF 클로로포름, 벤젠과 같은 일반 유기 용매에 매우 잘 녹았다. 전도성 투명 전극 (ITO)/공중합체 /알루미늄으로 구성된 단층형 유기 발광 소자는 공중합체에서 트리아진의 함유량이 $30\%$일 때 캐리어 균형이 잘 맞았고 최고의 외부 양자 효율 ($0.003\%$)을 나타내었다. 특히 위에서 제작한 유기 발광 소자는 페릴렌 발광체에 상응하는 청색 발광 (479 nm)을 나타냈다. 구동 전압은 5V로 매우 낮았고, 색 좌표는 X 값이 0.16, Y 값이 0.17이었다.

• Journal of Photoscience
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• 제7권2호
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• pp.59-61
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• 2000

As a potential electroluminescent material, tetrahydrochrysene (THC) is prepared using the dehydrocyclization following the acyloin condensation of methyl-3-phenyl propionate as key step from trans-mehyl cinnamate in 3 steps. THC showed emission at 428 and 456 nm after the photo- and electro-excitation, respectively. The luminance of THC doped on PVK was about /$25 cdm^2$ at 30 voltage with 70 nm of thickness. The results suggests that a new fluorescent organic dye, THC can be used organic electroluminescent device.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.366-369
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• 2001

In this study, the matrix Organic Electroluminescence (OEL) device, that was consisted of R,G,B pixels. We fabricated OEL devices by side by side methode and, used organic material Alq3 as green, DCM as red and Butyl PBD as blue ETL. We investigated the characteristic of brightness and current density for matrix OEL device. As the results, each color devices has minimum about $100cd/m^{2}$ brightness and maximum luminescence was $2500cd/m^2$ in green OEL device.

• ETRI Journal
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• 제31권6호
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• pp.642-646
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• 2009

Highly efficient white phosphorescent organic light-emitting diodes with a mixed-host structure are developed and the device characteristics are studied. The introduction of a hole-transport-type host (N, N'-dicarbazolyl-3-3-benzen (mCP)) into an electron-transport-type host (m-bis-(triphenylsilyl)benzene (UGH3)) as a mixed-host emissive layer effectively achieves higher current density and lower driving voltage. The peak external quantum and power efficiency with the mixed-host structure improve up to 18.9% and 40.9 lm/W, respectively. Moreover, this mixed-host structure device shows over 30% enhanced performance compared with a single-host structure device at a luminance of 10,000 $cd/m^2$ without any change in the electroluminescence spectra.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.366-369
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• 2001

In this study, the matrix Organic Electroluminescence (OEL) device, that was consisted of R,G,B pixels. We fabricated OEL devices by side by side methode and, used organic material Alq3 as green, DCM as red and Butyl PBD as blue ETL. We investigated the characteristic of brightness and current density for matrix OEL device. As the results, each color devices has minimum about 100 cd/㎡ brightness and maximum luminescence was 2500cd/㎡ in green OEL device