• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.752-755
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• 2007

In this paper, to compare thermal and chemical stabilities of poly-ethylene-terephtalate (PET) and polyether- surphone (PES), we fabricated Polymer Light Emitting Diode (PLED) on each substrate and analyzed these characteristics. Moreover, we analyzed the characteristics of the device deposited LiF (1 nm) before cathode deposition.

• 마이크로전자및패키징학회지
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• 제12권3호
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• pp.213-217
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• 2005

ITO(indium tin oxide)/Glass 기판위에 정공 수송층으로 PEDOT:PSS[poly(3,4-ethylenedioxythiophene):poly(styrene sulfolnate)]과 발광층으로 MEH-PPV[poly(2-methoxy-5-(2-ethyhexoxy)-1,4phenylenvinylene)]의 고분자를 사용하여 ITO/PEDOT:PSS/MEH-PPV/Al 구조를 갖는 고분자 유기 발광다이오드 (polymer light emitting diode: PLED)를 제작하였다. 고분자 유기 발광다이오드 제작시 MEH-PPV의 농도$(0.1\;wt\%\~0.9\;wt\%)$가 발광층 표면 거칠기와 박막층판의 마찰계수(friction coefficient)에 미치는 영향을 조사하였다. MEH-PPV의 농도를 $0.1\;wt\%$에서 $0.9\;wt\%$로 증가함에 따라 발광층의 RMS 값은 1.72 nm 에서 1.00 nm로 감소하여 거칠기가 개선되는 경향을 보여 주었다. 또한 발광층 박막의 마찰계수는 0.048에서 0.035로 감소하여 박막의 접합상태가 나빠지는 현상을 나타내었다. $0.5\;wt\%$의 농도를 갖는 PLED 다이오드에서 최대 휘도인 $409\;cd/m^2$ 값을 얻었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1448-1449
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• 2008

Inkjet printing is commonly used in depositing the solution of functional materials on the specific locations of a substrate, and also it can provide easy and fast patterning of polymer films over a large area. Inkjet printing is applicable to fabricating an organic light emitting diode (OLED), since conducting materials used as emissive electroluminescent layers can be manufactured into inks for ink jetting. By using the inkjet technology, we have succeeded in patterning a poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS) layer and a poly[2-Methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) layer on the Indume tin oxide (ITO) patterned substrates, and fabricating organic light emitting diodes.

• 마이크로전자및패키징학회지
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• 제10권4호
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• pp.35-38
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• 2003

ITO/glass 기판 위에 발광물질로서 poly(2-methoxy-5-(2-ethylhexoxy)-1,4-phenylenevinylene (MEH-PPV)를 이용하여 스핀코팅법(spin coating)으로 Glass/ITOM/MEH-PPV/Al 구조를 가지는 고분자 유기 발광 다이오드를 제작하였다. MEH-PPV 박막형성시 열처리온도에 따른 다이오드의 전기적, 광학적 특성을 조사하였다. 열처리 온도를 $65^{\circ}C$에서 $170^{\circ}C$로 증가함에 따라 유기 발광다이오드의 발광휘도는 10V 인가전압에서 630 cd/$\m^2$에서 280 cd/$\m^2$로 크게 감소하였다. 또한 $65^{\circ}C$에서 열처리한 시료의 경우 약 2 lm/W의 최대 발광효율을 나타내었다. 이러한 결과는 높은 온도에서 열처리시 MEH-PPV 유기 형광층과 전극간의 상호반응에 의한 계면 거칠기의 증가와 새로운 절연층의 형성 등과 관련이 있는것으로 판단된다.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1495-1499
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• 2011

A solution processable polymer was synthesized, by incorporating pyrene groups into the backbone of the polyaniline chain, and used as an emissive layer in an organic light emitting diode. The polyaniline base was reacted with acid chloride of pyrene butyric acid to form pyrene-functionalized polyaniline chains. The source of pyrene moiety was acid chloride of pyrene butyric acid. The formation of polymer from acid chloride of pyrene butyric acid and polyaniline was confirmed by the FTIR and $^1H$-NMR spectroscopy. Differential scanning calorimetry revealed high glass transition temperature of 210 $^{\circ}C$. Due to the presence of pyrene moieties in the backbone, the polyaniline synthesized in the present study is solution processable with light emitting property. The photoluminescence spectrum of the polymer revealed that emission lies in the blue region, with a peak at 475 nm. The light emitting device of this polymer exhibits the turn-on voltage of 15 V.

• 폴리머
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• 제36권4호
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• pp.519-524
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• 2012

공액고분자 전해질 전자수송층을 이용하는 고분자 발광소자의 정전용량을 측정하는 것은 전류밀도-전압-발광특성을 측정하는 방법과 더불어 전자수송층으로서 공액고분자 전해질의 기능을 이해하기 위한 소자물리 연구에서 중요한 정보를 제공해준다. 본 연구에서는 고분자 전해질의 반대 이온의 종류에 따라 저주파수 영역에서 정전용량의 거동이 변화하는 것으로부터 전하 주입의 메카니즘에서 차이점이 있음을 분석하였다. 정전용량 모델을 이용한 분석은 전자주입 메카니즘이 음극/전자수송층/발광층 사이의 계면에서 발생하는 쌍극자 배열 또는 전하수송체의 축적에 의한 것임을 나타내었다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.582-584
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• 2004

The light-emitting properties of poly(2-triethylgermyl-1,4-phenylenevinylene) (TEG-PPV) are compared with those of the silyl-substituted PPV homologue, poly(2-trimethylsilyl-1,4phenylenevinylene) (TMS-PPV). The precursor polymer is solution-processable. After carrying out thermal elimination on the precursor polymer film, the resulting fully conjugated polymer film was found to exhibit high thermal stability in air, and absorption that is shifted to the longer wavelength region owing to the extension of the n-conjugated system. TEG-PPV exhibits efficient green light emission; the maximum PL emission of a TEG-PPV thin film was found to be at 515 nm. The HOMO and LUMO energy levels were also determined using photo-emission spectroscopy. The performance of the TEG-PPV EL device was found to be comparable to that of the TMS-PPV device.

• Macromolecular Research
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• 제13권2호
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• pp.114-119
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• 2005

We synthesized two new series of alternating copolymers, poly[bis(2-(4-phenylenevinylene)-2-cyanoethenyl)-9,9-dihexyl-9H-fluoren-2,7-yl-alt-1,4-phenylene](Polymer-I)and poly[bis(2-(4-phenylenevinylene)-2­cyanoethenyl)-9,9-dihexyl-9H-fluoren-2,7-yl-alt-2,7-(9,9-dihexylfluorene)](Polymer-II), via the Suzuki coupling reaction, for use in light-emitting diodes (LEDs). Defect-free uniformly thin films of these polymers were found to be easily formed on indium-tin oxide (ITO) coated glass substrates. Multi-layer LEDs with ITO/PEDOT/Polymer/ LiF/Al configurations with or without an $Alq_3$ electron transport layer were fabricated with these polymers. The maximum EL emissions of Polymer-I and Polymer-II with an $Alq_3/LiF/Al$ cathode were observed at 516 and 533 nm, respectively. The maximum brightness and external luminance efficiency of the devices fabricated with the EL polymers were found to be $411 cd/m^2$ and 0.16 cd/A, respectively.

• 한국재료학회지
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• 제19권6호
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• pp.313-318
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• 2009

Polymer Light Emitting Diodes (PLEDs) with an ITO/PEDOT:PSS/PVK/PFO-poss/LiF/Al structure were prepared on plasma-treated ITO/glass substrates using spin-coating and thermal evaporation methods. The annealing effects of the PFO-poss film when it acts as the emission layer were investigated by using electrical and optical property measurements. The annealing conditions of the PFO-poss emission film were 100 and $200^{\circ}C$ for 1, 2 and 3 hours, respectively. The luminance increased and the turn-on voltage decreased when the annealing temperature and treatment time increased. After examining the Luminance-Voltage (L-V) properties of the PLED, the maximum luminance was found to be 1497 cd/$m^2$ at 11 V for the device when it was annealed at $200^{\circ}C$ for 3 hours. The peak intensity of the PLED emission spectra at approximately 525 nm in wavelength increased when the annealing temperature and time of the PFO-poss film increased. These results suggest that the light emission color shifted from blue to green.

• 한국재료학회지
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• 제20권6호
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• pp.294-300
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• 2010

In this study, we fabricated a polymer light emitting diode (PLED) and investigated its electrical and optical characteristics in order to examine the effects of the PFO [poly(9,9-dioctylfluorene-2-7-diyl) end capped with N,N-bis(4-methylphenyl)-4-aniline] concentrations in the emission layer (EML). The PFO polymer was dissolved in toluene ranging from 0.2 to 1.2 wt%, and then spin-coated. To verify the influence of the TPBI [2,2',2"-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole)]electron transport layer, TPBI small molecules were deposited by thermal evaporation. The current density, luminance, wavelength and current efficiency characteristics of the prepared PLED devices with and without TPBI layer at various PFO concentrations were measured and compared. The luminance and current efficiency of the PLED devices without TPBI layer were increased, from 117 to $553\;cd/m^2$ and from 0.015 to 0.110 cd/A, as the PFO concentration increased from 0.2 to 1.0 wt%. For the PLED devices with TPBI layer, the luminance and current efficiency were $1724\;cd/m^2$ and 0.501 cd/A at 1.0 wt% PFO concentration. The CIE color coordinators of the PLED device with TPBI layer at 1.0 wt% PFO concentration showed a more pure blue color compared with the one without TPBI, and the CIE values varied from (x, y) = (0.21, 0.23) to (x, y) = (0.16, 0.11).