• 한국응용과학기술학회지
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• 제34권3호
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• pp.562-567
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• 2017

The organic light-emitting diodes are fabricated with six anthracene derivatives containing simple substituents such as phenyl or naphthyl group. The device structure is as in the following: Indium tin oxide (ITO) (180 nm)/4,4-4,4',4"-tris[N-(1-naphthyl)-N-phenylamino]triphenylamine (2-TNATA) (30 nm)/4,4'-bis[N-(1-naphthyl)-N-phenyl-1-amino] biphenyl (NPB) (20 nm)/Emitting compound (30 nm)/2,2',2"-(1,3,5-Benzinetriyl)-tris (1-phenyl-1-H-benz-imidazole) TPBi (40 nm)/lithium quinolate (Liq) (2 nm)/Al (100 nm). In the emitting layer the anthracene derivatives are used without any dopant. All the six devices show blue emissions. Among the tested diodes, the one with 9-(2-naphthyl)-10-(p-tolyl) anthracene (2-NTA) exhibited luminous efficiency, power and external quantum efficiencies of 3.26 cd/A, 0.98 lm/A, 2.8 % at $20mA/cm^2$.

• 제어로봇시스템학회논문지
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• 제14권6호
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• pp.511-514
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• 2008

2-wavelength type white OLED devices have been made consisted of two layers; a layer with blue light emitting DPVBi host and other EML layer with yellow emitting rubrene dopant. New method to get white emitting device has been suggested by varying thicknesses of the DPVBi layer. The ITO/2-TNATA($150{\AA}$)/NPB($350{\AA}$)/DPVBi($35{\AA}$)/DPVBi:rubrene (2wt%,$200{\AA}$)/DPVBi($100{\AA}$)/Alq_3($50{\AA}$)/LiF($5{\AA}$)/Al($1000{\AA}$) structure has showed optimum results in CIE coordinates of (0.3233, 0.33). OLED devices with this structure has properties of $1.2d/m^2$ at turn-on voltage of 3.9V and $1037cd/m^2$ at 7.9V. This structure has advantages of simple fabrication and easy to emit the white color.

• 한국전기전자재료학회논문지
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• 제18권10호
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• pp.941-944
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• 2005

In this experiment, OLEDs(Organic Light Emitting Diodes) was fabricated to confirm effect of Plasma treatment which increase the hole injection characteristic from anode. Device structure was $ITO/2-TNATA/{\alpha}-NPD/DPVBi/BAlq/Alq_3/Al:Li$. We used DPVBi (4, 4 - Bis (2,2-diphenylethen-1-yls) - Biphenyl) as a blue emitting material. To optimize the process condition of plasma treatment, we used 2 gases of the oxygen and nitrogen gas under 120 mTorr with 100 W, 200 W, and 400 W plasma power. The current efficiency of $N_2$ plasma is more efficient than that of $O_2$ plasma. At $1000 cd/m^2$, we obtained the maximum current efficiency of 6.45 cd/A using $N_2$ gas with 200 W plasma power.

• 한국전기전자재료학회논문지
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• 제20권1호
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• pp.53-56
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• 2007

We have fabricated organic white light emitting diodes by mixing two colors from very thin rubrene doped and non-doped DPVBi layers. The device structure was ITO/2-TNATA(15 nm)/${\alpha}$-NPD(35 nm)/DPVBi:rubrene(5 nm)/DPVBi(30 nm)/$Alq_{3}(5\;nm)$/BCP(5 nm)/LiF(0.5 nm)/Al(150 nm). The yellow-emitting rubrene of 0.7 wt % was doped into the blue-emitting DPVBi host for the white light. CIE coordinate of the device was (0.31, 0.33) at 8 V. The color coordinates were stable at wide ranges of driving voltages. The luminance was over $1,000\;cd/m^{2}$ at 8 V and increases to $14,500\;cd/m^{2}$ at 12 V. The maximum current efficiency of the device was 8.2 cd/A at $200\;cd/m^{2}$.

• 한국표면공학회지
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• 제40권2호
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• pp.77-81
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• 2007

To investigate the characteristics of green light-emitting OLED device, C545T material with $Alq_3$ was doped in the OLED device of $ITO(1500)/2-TNATA(400{\AA})/NPB(80{\AA})/Alq_3:C545T(160{\AA})/Alq_3(240{\AA})/LiF(3{\AA})/Al(2400{\AA})$ structure, which was used as a activator at the respective concentration of 0.5 vol.%, 1 vol.%, 2 vol.% and 3 vol.%. It was observed from the experiments that the device efficiency firstly increased with the increase of C545T concentration and the maximum efficiency of 10.9 cd/A and 4.28 lm/W was obtained at C545T concentration of 1 vol.%, and then the device efficiency decreased as the C545T activator concentration increased above 2 vol.% contents, while the longest lifetime of over 750 hours was obtained at C545T concentration of 1 vol.%.

• 반도체디스플레이기술학회지
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• 제7권3호
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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.

• Bulletin of the Korean Chemical Society
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• 제31권12호
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• pp.3711-3717
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• 2010

Four orange-red phosphorescent Ir(III) complexes were designed and synthesized based on the benzoylphenylpyridine ligand with a fluorine substituent. Multilayered OLEDs with the device structure, ITO/2-TNATA/NPB/CBP : 8% Ir(III) complexes/BCP/Liq/Al, were fabricated using these complexes as dopant materials. All the devices exhibited orange-red electroluminescence and their electroluminescent properties were quite sensitive to the structural features of the dopants in the emitting layers. Among these, the maximum luminance ($14700\;cd/m^2$ at 14.0 V) was observed in the device containing Ir(III) complex 1 as the dopant. In addition, its luminous, power and quantum efficiency were 11.7 cd/A, 3.88 lm/W and 9.58% at $20\;mA/cm^2$, respectively. The peak wavelength of electroluminescence was 606 nm with CIE coordinates of (0.61, 0.38) at 12.0 V. The device also showed stable color chromaticity with various voltages.

• Bulletin of the Korean Chemical Society
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• 제34권1호
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• pp.107-111
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• 2013

A new green-emitting material with donor-acceptor architecture, 3,7-bis(1'-phenylbenzimidazole-2'-yl)-10-phenylphenothiazine (BBPP) was synthesized and its thermal, optical, and electroluminescent characteristics were investigated. Organic light-emitting diodes (OLEDs) with four different multilayer structures were prepared using BBPP as an emitting layer. The optimized device with the structure of [ITO/2-TNATA (40 nm)/BBPP (30 nm)/TPBi (30 nm)/Alq3 (10 nm)/LiF (1 nm)/Al (100 nm)] exhibited efficient green emission. Enhanced charge carrier balance and electron mobility in the organic layers enabled the device to demonstrate a maximum luminance of 31,300 cd/$m^2$, a luminous efficiency of 6.83 cd/A, and an external quantum efficiency of 1.62% with the CIE 1931 chromaticity coordinates of (0.21, 0.53) at a current density of 100 mA/$cm^2$.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.424-424
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• 2010

유기발광소자는 전류구동소자로서 소자를 대형화할 때 소모 전력이 급격히 증가하여 다른 디스플레이 제품에 비해 더욱 더 높은 전력효율을 요구한다. 높은 전력효율과 낮은 구동전압을 갖는 유기발광소자를 제작하기 위해서 P-I-N구조의 유기발광소자에 관한 연구가 활발히 진행되고 있다. 본 연구에서는 일함수가 큰 투명 Indium Tin Oxide (ITO) 양극 위에 p 형 불순물인 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethane (F4-TCNQ) 를 4,4',4"-tris(N-(2naphthyl)-N-phenylamino)triphenylamine (2-TNATA)에 도핑하여 정공주입 및 정공수송을 향상하였으며, 그위에 N,N'-bis(1-naphthyl)-N,N'-diphenyl- 1,1'-biphenyl-4,4'-diamine (NPB) 층을 증착 후, tris-(8-hydroxyquinoline) aluminum ($Alq_3$) 발광층과 전자 수송층으로 사용하여 전자와 정공이 재결합을 하여 엑시톤을 형성하여 녹색 빛을 측정하였다. p 형 불순물은 정공 수송층의 에너지 장벽을 감소하며 발광층으로의 정공주입량을 증가하는 역할을 하여 구동전압을 감소하였으나 발광층내에서 전자와 정공의 비를 불균일하게 하여 발광효율은 약간 감소하였다. p형 불순물인 F4-TCNQ의 도핑의 농도에 따라 측정된 발광특성의 변화로부터 정공의 전송 메카니즘을 분석하였으며 이는 p형 불순물 첨가된 녹색 유기발광소자의 전하수송 메카니즘을 이해하는데 중요한 자료를 제공할 것이다.

• 한국전기전자재료학회논문지
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• 제25권5호
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• pp.381-386
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• 2012

To study encapsulation method for large-area organic light emitting diodes (OLEDs), red emitting OLEDs were fabricated, on which $Alq_3$ as organic buffer layer and LiF and Al as inorganic protective layers were deposited to protect the damage of OLED by epoxy. And then the OLEDs were attached to flat glass by printing method using epoxy. The basic structure of OLED doped with rubrene of 1 vol.% as emitting layer is ITO(150 nm) / 2-TNATA(50 nm) / ${\alpha}$-NPD(30 nm) / $Alq_3$:Rubrene(30 nm) / $Alq_3$(30 nm) / LiF(0.7 nm) / Al(100 nm). In case of depositing $Alq_3$, LiF and Al and then attaching of flat glass onto OLED, current density, luminance, efficiency and driving voltage were not changed and lifetime was increased according to thickness of Al as inorganic protective layers. The lifetime of OLED/$Alq_3$/LiF/Al_4/glass structure was 139 hours increased by 15.8 times more than bare OLED of 8.8 hours and 1.6 times more than edge sealed OLED of 54.5 hours.