• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.363-367
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• 2006

We synthesized new blue and bluish green emitting materials by using fully substituted ethylene moieties. Multi-layered EL devices were fabricated with synthesized materials and evaluated in terms of emission color and luminescence efficiency. BPBAPE[EML 4] having high $T_g$ of $155^{\circ}C$ showed luminance and power efficiency of 10.33cd/A and 4.0 lm/W without any doping agent. BTBPPA[EML 5] exhibited 5cd/A and 1.67lm/W efficiency with blue CIE value of (0.165, 0.195).

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 D
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• pp.1255-1257
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• 1998

In this study,$ 5{\times}5$ dot-matrix display was implemented with powder electroluminescent device (PELD). Generally PELD which have a luminance from powder phosphor with electric field, inserted phosphor and dielectric layer between electrodes is basic structure. To make high brightness PELD compared to conventional device, new type of PELD was proposed as follows. New PELD had only one layer, which was mixed phosphor (ZnS:Cu) and dielectric (BaTiO3) material appropriately between electrodes. To compare and estimate the conventional and new type of PELD, the EL spectrum, transferred charge density, brightness and decay time was measured. As above result, we fabricated a hish brightness $ 5{\times}5$ dot-matrix display with new type of PELD. Its brightness was 6400 $cd/m^2$ at 200 V, 400Hz.

• 반도체디스플레이기술학회지
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• 제7권1호
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• pp.35-40
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• 2008

In OLED vacuum evaporation process, the essential requirements include good uniformity of the film thickness over a glass substrate. And, it is commercially significant to improve the consuming efficiency of material of the evaporant which is deposited on the substrate because of high price of organic materials. In this paper, to achieve the better thickness uniformity and the better organic material consuming rate, a process optimization algorithm was developed by understanding vacuum evaporation process parameters that affect the material consuming efficiency and the uniformity of film thickness. Based on the method developed in this study, the vacuum evaporation process of OLED was successfully controlled. The developed method allowed the manufacture of high quality OLED displays with cheaper fabrication cost.

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2609-2615
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• 2013

A series of fluorene-carbazole copolymers containing the pendant phosphor chromophore $Ir(absn)_2(acac)$ (absn: 2-(1-naphthyl)benzothiazole; acac: acetylacetone) were designed and synthesized via Yamamoto coupling. In the film state, these copolymers exhibited absorption and emission peaks at approximately 389 and 426 nm, respectively, which originated from the fluorene backbone. However, in electroluminescent (EL) devices, a significantly red-shifted emission at approximately 611 nm was observed, which was attributed to the pendant iridium(III) complex. Using these copolymers as a single emission layer, polymer light-emitting devices with ITO/PEDOT:PSS/polymer:DNTPD/TmPyPb/LiF/Al configurations exhibited a saturated red emission at 611 nm. The attached iridium(III) complex had a significant effect on the EL performance. A maximum luminous efficiency of 0.85 cd/A, maximum external quantum efficiency of 0.77, maximum power efficiency of 0.48 lm/W, and maximum luminance of 883 $cd/m^2$ were achieved from a device fabricated with the copolymer containing the iridium(III) complex in a 2% molar ratio.

• 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.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2002년도 춘계 학술발표강연 및 논문개요집
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• pp.68-68
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• 2002

• 대한화학회지
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• 제49권2호
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• pp.233-238
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• 2005

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1015-1018
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• 2008

Tandem organic light-emitting diodes (OLEDs) do not always improve power efficiency over their conventional OLED counterparts. When a tandem OLED utilizes optimized EL units, increased power efficiency can only be achieved if the intermediate connector in the device has excellent charge injection capability.

• 조명전기설비학회논문지
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• 제14권1호
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• pp.1-6
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• 2000

Ethyl hydroxy ethyl cellulose의 고분자를 중심으로 하는 유기 결합제를 사용하고 형광체로서 ZnS:Cu와 유전체로$BaTiO_3$ 사용해 screen printing법에 의해 신광원으로서 많은 연구 개발이 집중되고 있는 유기분산형 백라이트 EL(Electroluminescent) 소자를 제조하였다. 제조된 백라이트용 유기 분산형 EL 소자의 특성은 $25[^{\circ}C]$, 100[V], 400[Hz]에서 $1.98[mA/\m^2]$의 전류밀도, O.075[W]의 power consumption, 정전용량 7.l[nF]를 나타내었다. 소자의 휘도는 50~150[V] 사이에서 $20~110[cd/\m^2]$의 밝기를 나타내였으며, 형광체의 색상변화는 ClE에 공인된 색 좌표에 의해 x=0.1711, y=0.3676의 bluish green의 색상을 나타내었다.

• 전기화학회지
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• 제3권1호
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• pp.1-4
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• 2000

Zinc chloride$(ZnCl_2)$를 출발물질로 하여 Bis(8-oxyquinolino) zinc II(Znq2)를 합성하였다. N-N'-diphenyl-N-N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine(TPD)를 전공운송층으로 도입하고, Znq2를 전자운송층 및 발광층으로 이용하여 유기 EL소자를 제작하였다. ELD의 발광을 최대화하기 위해 EL 발광층의 두께를 변화시켜 ITO(투명전극)/TPD(전공운송층)/znq2(발광층 및 전자운송층)/Al(배면전극) 순으로 제작하였다. PL 스펙트림으로 Znq2 화합물이 540 nm에서의 노란-녹색의 빛을 발하는 물질임을 알 수 있었다. 전압전류밀도와 전압-휘도의 전기적인 거동이 문턱전압 6 V에서 나타났고, 최대 휘도와 효율은 약 $838 cd/m^2$로 측정되었다. 이 결과로써, 합성된 Znq2가 유기 EL디스플레이용 재료 물질로써 이용 가능성 있는 물질임을 밝힌다.