• Title/Summary/Keyword: Alq$_3$

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Fabrication and Properties of OLEDs using PECCP Langmuir-Blodgett(LB) Films (PECCP LB 박막을 이용한 유기 발광 타이모드의 제작과 이의 특성)

  • Lee, Ho-Sik;Lee, Won-Jae;Park, Myung-Gyu;Songe, Min-Jeng;Park, Jong-Wook
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.831-834
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    • 2000
  • Characteristics of organic light-emitting diodes(OLEDs) were studied with devices made by PECCP[poly(3,6-N-2-ethylhexyl carbazolyl cyanoterephthalidene)] Langmuir-Blodget(LB) films. The emissive organic material was synthesized and named PECCP, which has a strong electron donor group and an electron accepter group in main chain repeated unit. The LB technique was employed to investigate the identification of the recombination zone in the ITO/PECCP LB films/Alq$_3$/Al structure by varying the LB film thickness. PECCP was considered as an emissive layer and Alq$_3$was used as an electron-transport layer. We measured current-voltage(I-V) characteristics, UV/visible absorption, PL spectrum, and EL spectrum of those devises.

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Electrical Properties of OLEDs due to the Hole-size of Crucible Boat and Deposition Rate of Hole Transport Layer (Crucible Boat 홀 크기와 정공 수송층 증착속도에 따른 유기밭광 다이오드의 전기적 특성)

  • Kim, Weon-Jong;Shin, Hyun-Teak;Shin, Jong-Yeol;Hong, Jin-Woong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.1
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    • pp.74-80
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    • 2009
  • In the structure of ITO/N,N'-diphenyl-N,N' bis (3-methylphenyl)-1,1'-biphenyl-4,4'-diamine(TPD)/tris (8-hydroxyquinoline)aluminum($Alq_3$)/Al device, we studied the efficiency improvement of organic light-emitting diodes due to variation of deposition rate of hole transport layer (TPD) materials using hole-size of crucible boat. The thickness of TPD and $Alq_3$ was manufactured 40 nm, 60 nm, respectively under a base pressure of $5{\times}10^{-6}$ Torr using a thermal evaporation. The $Alq_3$ used for an electron-transport and emissive layer were evaporated to be at a deposition rate of $2.5\;{\AA}/s$. When the deposition rate of TPD increased from 1.5 to $3.0\;{\AA}/s$, we studied the efficiency improvement of TPD using the hole-size of crucible is 1.0 mm. When the deposition rate of TPD is $2.5\;{\AA}/s$, we found that the average roughness is rather smoother, the luminous efficiency the external quantum efficiency is superior to the others. Compared to the two from the devices made with the deposition rate of TPD is $2.0\;{\AA}/s$ and $3.0\;{\AA}/s$, the external quantum efficiency was improved by four-times and two-times, respectively.

Electrical Characteristics of OLEDs depending on the Deposition Rate of Hole Transport Layer(TPD) (정공 수송층(TPD) 증착 속도에 따른 유기 발광 소자의 전기적 특성)

  • Kim, Weon-Jong;Lee, Young-Hwan;Lee, Sang-Kyo;Park, Hee-Doo;Cho, Kyung-Soon;Kim, Tae-Wan;Hong, Jin-Woong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.87-88
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    • 2008
  • In the structure of ITO/N,N'-diphenyl-N,N' bis (3-methylphenyl)-1,1'-biphenyl-4,4'-diamine(TPD)/tris (8-hydroxyquinoline)aluminum$(Alq_3)$/Al device, we studied the efficiency improvement of organic light-emitting diodes due to variation of deposition rate of TPD materials. The thickness of TPD and $Alq_3$ was manufactured 40 nm, 60 nm, respectively under a base pressure of $5\times10^{-6}$Torr using a thermal evaporation. The $Alq_3$ used for an electron-transport and emissive layer were evaporated to be at a deposition rate of 2.5 $\AA$/s. When the deposition rate of TPD increased from 1.5 to 3.0 $\AA$/s, we found that the average roughness is rather smoother, external quantum efficiency is superior to the others when the deposition rate of TPD is 2.5 $\AA$/s. Compared to the ones from the devices made with the deposition rate of TPD 3.0 $\AA$/s, the external quantum efficiency was improved by a factor of eight.

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Emission Characteristics of Encapsulated Organic Light Emitting Devices Using Attaching Film and Flat Glass (접착 필름과 평판 유리를 이용하여 봉지된 유기 발광 소자의 발광 특성)

  • Lim, Su Yong;Yang, Jae-Woong;Ju, Sung-Hoo
    • Journal of the Korean institute of surface engineering
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    • v.46 no.3
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    • pp.111-115
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    • 2013
  • To study the encapsulation method for large-area organic light emitting devices (OLEDs), OLED of ITO / 2-TNATA / NPB / $Alq_3$:Rubrene / $Alq_3$ / LiF / Al structure was fabricated, which on $Alq_3$/LiF/Al as protective layer of OLED was deposited to protect the damage of OLED, and subsequently it was encapsulated using attaching film and flat glass. The current density and luminance of encapsulated OLED using attaching film and flat glass has similar characteristics compared with non-encapsulated OLED when thickness of Al as a protective layer was 1200 nm, otherwise power efficiency of encapsulated OLED was better than non-encapsulated OLED. Encapsulation process using attaching film and flat glass did not have any effects on the emission spectrum and the Commission International de L'Eclairage (CIE) coordinate. The lifetime of encapsulated OLED using attaching film and flat glass was 287 hours in 1200 nm Al thickness, which was increased according to thickness of Al protective layer, and was improved 54% compared with 186 hours in same Al thickness, lifetime of encapsulated OLED using epoxy and flat glass. As a result, it showed the improved efficiency and the long lifetime, because the encapsulation method using attaching film and flat glass could minimize the impact on OLED caused through UV hardening process in case of glass encapsulation using epoxy.

Encapsulation Method of Flexible OLED Using SiNx and Metal Film (SiNx와 금속막을 이용한 플렉시블 OLED 봉지 방법)

  • Lee, Hyoe Sun;Ju, Sung-Hoo
    • Journal of the Korean institute of surface engineering
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    • v.47 no.3
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    • pp.99-103
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    • 2014
  • The encapsulation method of flexible organic light emitting devices (OLEDs) was investigated for the structure of ITO / 2-TNATA / NPB / $Alq_3$ : Rubrene (1 vol.%) / $Alq_3$ / LiF / Al / $Alq_3$ / LiF / Al (OLED #1), on which $SiN_x$ thin film was deposited and metal film was attached to protect the damage of OLED from oxygen and moisture. The $SiN_x$ thin film was deposited by plasma enhanced chemical vapor deposition (PECVD) method using $SiH_4$ of 20 sccm and $N_2$ of 15~35 sccm as reactor gases. The optimum $SiN_x$ deposition condition was found to be 20 sccm $SiH_4$ and 20 sccm $N_2$ from the Ca test of the fabricated $SiN_x$ thin film. The life time of OLED #1, OLED #1 / $SiN_x$ 200 nm, OLED #1 / $SiN_x$ 400 nm and OLED #1 / $SiN_x$ 400 nm / metal film was 7, 12, 25, and 45 hours, respectively. In conclusion, it has been shown that the lifetime of OLEDs can be improved more than 6 times by $SiN_x$ film and a metal film encapsulation.

전면 발광 유기 발광 소자에서 두께에 따른 발광 스펙트럼 연구

  • Yang, Ji-Won;Han, Won-Geun;Lee, Won-Jae;Lee, Ho-Sik;Kim, Tae-Wan
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.20-21
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    • 2009
  • 우리는 전면 발광 소자에서 두께에 따른 발광 스펙트럼을 연구하였다. 소자 구조는 Al(100nm)/TPD(40nm)/Alq3(60nm)/LiF(0.5nm)/Al(2nm)/Ag(30nm)으로 하였다. N,N'-diphenyl-N,N'-di(m-tolyl)-benzidine(TPD)와 tris-(8-hydroxyquinoline) aluminium(Alq3)는 전공 수송층과 발광층으로 각각 사용되었다. 반투명 전극은 Li/Al/Ag로 하였다. 유기물층과 전극은 $2\times10-5$torr의 진공도에서 열 증착하였다. 유기물과 금속의 증착 속도는 $0.5\sim1.0{\AA}/s$$0.5\sim5{\AA}/s$로 하였다. 제작된 소자는 두께가 증가할 수록 장파장으로 이동하는 현상을 보였다. 이러한 현상은 마이크로 캐비티 이론으로 설명할 수 있다. 소자는 이론적인 마이크로 캐비티 수식을 이용하여 분석하기 위해 각각의 변수를 이용하여 실험과 이론을 비교하였을 때, 각각의 스펙트럼이 거의 일치하는 것을 확인할 수 있었다.

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Red OLEDs containing the dotted-line doped layer structure in its emitting region.

  • Lee, Chang-Min;Han, Jeong-Whan
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.612-615
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    • 2004
  • We present an extremely high efficient red organic light-emitting diodes (OLEDs) using a fluorescent dye 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) doped into an emitting region which consists of multiple pairs of a doped and an undoped layer. An emitting region of OLEDs composes of a tris-(8-hydroxyquinolinato) aluminum (Alq3) codoped with rubrene of 5% wt. or a mixture of Alq3 and rubrene (1:1). The luminance yield of the codoped device and the mixed device are 6.5 cd/A and 9.2 cd/A at 10 mA/$cm^2$, respectively. We have considerably improved the luminance yields of red OLEDs as much as ${\sim}$90% at 10 mA/$cm^2$ compared with that of the device doped with only DCJTB. We attribute it to both the emitting assist dopant (rubrene) and the dotted-line doping structure in an emitting region of OLED.

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Efficient orange-red OLED using a new DCM derivative as a doping molecule

  • Hwang, Do-Hoon;Lee, Jong-Don;Lee, Moon-Jae;Lee, Chang-Hee
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.579-581
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    • 2004
  • A new DCM derivative containing the phenoxazine moiety (DCPXZ) has been synthesized for use as a red fluorescent dye molecule in organic light-emitting diodes (OLEDs). The photoluminescence and electroluminescence properties of DCPXZ were examined. The maximum photoluminescence of DCPXZ in chloroform solution ($10^{-5}$ mol) was observed at 616 nm. EL devices were fabricated with the structure ITO/PEDOT-PSS/Cu-PC(15nm)/${\alpha}$-NPD(45nm)/$Alq_3$:DCPXZ(30nm)/$Alq_3$(30nm)/LiF(0.5nm)/Al. The maximum EL emission for the 2.0% DCPXZ-doped device was at 608 nm with CIE coordinates (0.57, 0.42). The EL device exhibited a maximum brightness of 15,000 cd/$m^2$ at 19.4 V and a power efficiency of 1.04 lm/W at a luminance of 100 cd/$m^2$.

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Enhancement of the luminous efficiency of organic light-emitting diodes utilizing a wide-bandgap impurity doped emitting layer

  • Choo, D.C.;Bang, H.S.;Kwack, B.C.;Kim, T.W.;Seo, J.H.;Kim, Y.K.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1447-1450
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    • 2007
  • The electrical properties of organic lightemitting devices (OLEDs) with wide-bandgap impurity-doped emitting layers (EML) were investigated. While the luminous efficiency of OLEDs with a NPB or a DPVBi-doped $Alq_3$ EML did not vary significantly with the current density, that of the OLEDs with a BCP-doped $Alq_3$ EML changed dramatically.

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Hole transport properties of organic EL devices using a copper(II)-phthalocyanine (Copper(II)-phthalocyanine을 이용한 유기 EL 소자의 정공 전송 특성)

  • 한우미;임은주;이정윤;김명식;이기진
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.927-930
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    • 2001
  • We studied the electrical properties of Copper(II)-phthalocyanine (Cu-Pc) as a hole transport layer in organic light emitting devices (OLEDs). OLEDs were constructed with ITO/CU-Pc/triphenyl-diamine (TPD)/tris-(8-hydroxyquinoline) aluminum ( Alq$_3$) + 4- (Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM)/Al. It was consisted of a thin DCM in Alq$_3$emission layer. We observed that the change of recombination zone was moved toward the cathode as the hole mobility increased due to the heat-treatment temperature of Cu-Pc layer increased.

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