• Title/Summary/Keyword: BPhen

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A Hybrid Spacer Effect on White Organic Light-Emitting Diodes with Phosphorescent Emitters (인광 발광 물질을 이용한 백색 유기 발광 다이오드에서의 혼합된 스페이서의 영향에 관한 연구)

  • Seo, Ji-Hoon;Park, Jung-Sun;Hyung, Gun-Woo;Seo, Ji-Hyun;Lee, Kum-Hee;Yoon, Seung-Soo;Kim, Young-Kwan
    • Journal of the Korean Applied Science and Technology
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    • v.26 no.1
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    • pp.24-28
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    • 2009
  • 본 논문에서는 청색 인광 발광 물질인 bis(3,5-Difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl) iridium (III) (Flrpic)과 녹색 인광 발광 물질인 fac-tris(2-phenypyridine) irdium(III) ($Ir(ppy)_3$)와 적색 인광 발광 물질인 his(5-benzoyl-2-phenylpyridinato-C,N)iridium(III) (acetylacetonate) ($(Bzppy)_{2}Ir(acac)$)를 각각 적층하여 백색 유기 발광 다이오드를 제작하였고, 각각의 발광층 사이에 혼합된 스페이서인 4,4'-N,N'-dicarbazole-biphenyl (CBP):4,7-diphenyl-1,10-phenanthroline (BPhen)을 적층하여 그 때의 영향에 대하여 연구하였다. 최적화된 구조에서의 전력 효율은 $0.014\;mA/cm^2$에서의 19.7 lm/w를 나타내었으며, $0.127\;mA/cm^2$에서의 11.5%의 외부 양자 효율을 나타내었고, 8 V에서 Commission Internationale do I'Eclairage ($CIE_{x,y}$) coordinates (x=0.36, y=0.44)의 색좌표를 나타내었다.

Emission Properties of White Organic Light-Emitting Diodes with Blue Emitting Layer (청색 발광층에 의한 백색 OLED의 발광 특성)

  • Chun, Hyun-Dong;Na, Hyunseok;Ju, Sung-Hoo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.6
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    • pp.451-456
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    • 2013
  • To study emission properties of white phosphorescent organic light emitting devices (PHOLEDs), we fabricated white PHOLEDs of ITO(150 nm) / NPB(30 nm) / TcTa(10 nm) / mCP(7.5 nm) / light-emitting layer(25 nm) / UGH3(5 nm) / Bphen(50 nm) / LiF(0.5 nm) / Al(200 nm) structure. The total thickness of light-emitting layer with co-doping and blue-doping/co-doping using a host-dopant system was 25 nm and the dopant of blue and red was FIrpic and $Bt_2Ir$(acac) in UGH3 as host, respectively. The OLED characteristics were changed with position and thickness of blue doping layer and co-doping layer as light-emitting layer and the best performance seemed in structure of blue-doping(5 nm)/co-doping(20 nm) layer. The white PHOLEDs showed the maximum current density of $34.5mA/cm^2$, maximum brightness of $5,731cd/m^2$, maximum current efficiency of 34.8 cd/A, maximum power efficiency of 21.6 lm/W, maximum quantum efficiency of 15.6%, and a Commission International de L'Eclairage (CIE) coordinate of (0.367, 0.436) at $1,000cd/m^2$.

Emission Characteristics of Blue Fluorescent OLED with Anode Materials (양극 물질에 따른 청색 형광 OLED의 발광 특성)

  • Kong, Do-Hoon;Lee, Yo-Seb;Ju, Sung-Hoo;Yang, Jae-Woong
    • Journal of Surface Science and Engineering
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    • v.48 no.3
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    • pp.121-125
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    • 2015
  • We studied the blue fluorescent OLED with Mg:Ag, Al, Ni as anode materials. Blue fluorescent OLEDs were fabricated using Anode / $MoO_3$ (3 nm) / 2-TNATA (60 nm) / NPB (30 nm) / SH-1 : BD-2 (5 vol.%, 30 nm) / Bphen (40 nm) / Liq (1 nm) / Al (150 nm). Current density of OLED with Mg:Ag was not measured due to too low work function, and that of OLED with Al showed $45.2mA/cm^2$ at 12 V. Luminance and Current efficiency of OLED with Al showed $385.1cd/m^2$ and 0.9 cd/A. Current density of OLED with Ni of 8, 10, 12 nm thickness showed 10, 12.9, $37.2mA/cm^2$, respectively. Luminance and Current efficiency of OLED with Ni of 8, 10, 12 nm thickness showed 670.9, 991.2, $1,320cd/m^2$ and 6.7, 7.7, 3.6 cd/A, respectively. Transmittance of Al was 52.2% at 476 nm wavelength and that of Ni of 8, 10, 12 nm thickness was 79, 77, 74 %, respectively. In spite of best current density, OLED with Al showed the lowest luminance and current efficiency because of low work function and poor transmittance. When thickness of Ni was increased to 12nm, current efficiency was sharply lower owing to bad transmittance and unbalance of holes and electrons. Finally, OLED with Ni of 10 nm thicknes showed the highest current efficiency.

The Characteristics of Organic Light-emitting Diodes With a New Blue Phosphorescent Material (새로운 청색의 인광 물질을 어용한 유기 발광 소자의 전기적 특성 및 수명에 대한 연구)

  • Kim, Y.K.;Park, J.H.;Seo, J.H.;Seo, J.H.;Han, J.W.;Im, C.;Han, S.H.;Lee, S.H.
    • Journal of the Korean Applied Science and Technology
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    • v.24 no.1
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    • pp.74-78
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    • 2007
  • A new blue phosphorescent material for organic light emitting diodes (OLEDs), Iridium(III)bis[2-(4-fIuoro-3-benzonitrile)-pyridinato-N,C2'] picolinate (Firpic-CN), was synthesized and studied. We compared characteristics of Firpic-CN and Bis(3,5-Difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl) iridium III (FIrpic) which has been used for blue dopant materials frequently. The devices structure were indium tin oxide (ITO) (1000 ${\AA}$)/N,N'-diphenyl-N,N'-(2-napthyl)-(1,1'-phenyl)-4,4'-diamine (NPB) (500 ${\AA}$)/4,4'-N,N'-dicarbazole-biphyenyl (CBP) : FIrpic and FIrpic-CN (X wt%)/4,7-diphenyl-1,10-phenanthroline (BPhen) (300 ${\AA}$)/lithum quinolate (Liq) (20 ${\AA}$)/Al (1000 ${\AA}$). 15 wt% FIrpic-CN doped device exhibits a luminance of $1450\;cd/m^2$ at 12.4 V, luminous efficiency of 1.31 cd/A at $3.58mA/cm^2$, and Commission Internationale d'Eclairage $(CIE_{x,y})$ coordinates of (0.15, 0.12) at 12 V which shows a very deep blue emission. We also measured lifetime of devices and was presented definite difference between devices of FIrpic and FIrpic-CN. Device with FIrpic-CN as a dopant presented lower longevity due to chemical effect of CN ligand.

Fabrication and Characterization of High Luminance WOLED Using Single Host and Three Color Dopants (단일 호스트와 3색 도펀트를 이용한 고휘도 백색 유기발광다이오드 제작과 특성 평가)

  • Kim, Min Young;Lee, Jun Ho;Jang, Ji Geun
    • Korean Journal of Materials Research
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    • v.26 no.3
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    • pp.117-122
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    • 2016
  • White organic light-emitting diodes with a structure of indium-tin-oxide [ITO]/N,N-diphenyl-N,N-bis-[4-(phenylm-tolvlamino)-phenyl]-biphenyl-4,4-diamine [DNTPD]/[2,3-f:2, 2-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile [HATCN]/1,1-bis(di-4-poly-aminophenyl) cyclo -hexane [TAPC]/emission layers doped with three color dopants/4,7-diphenyl-1,10-phenanthroline [Bphen]/$Cs_2CO_3$/Al were fabricated and evaluated. In the emission layer [EML], N,N-dicarbazolyl-3,5-benzene [mCP] was used as a single host and bis(2-phenyl quinolinato)-acetylacetonate iridium(III) [Ir(pq)2acac]/fac-tris(2-phenylpyridinato) iridium(III) $[Ir(ppy)_3]$/iridium(III) bis[(4,6-di-fluoropheny)-pyridinato-N,C2] picolinate [FIrpic] were used as red/green/blue dopants, respectively. The fabricated devices were divided into five types (D1, D2, D3, D4, D5) according to the structure of the emission layer. The electroluminescence spectra showed three peak emissions at the wavelengths of blue (472~473 nm), green (495~500 nm), and red (589~595 nm). Among the fabricated devices, the device of D1 doped in a mixed fashion with a single emission layer showed the highest values of luminance and quantum efficiency at the given voltage. However, the emission color of D1 was not pure white but orange, with Commission Internationale de L'Eclairage [CIE] coordinates of (x = 0.41~0.45, y = 0.41) depending on the applied voltages. On the other hand, device D5, with a double emission layer of $mCP:[Ir(pq)_2acac(3%)+Ir(ppy)_3(0.5%)]$/mCP:[FIrpic(10%)], showed a nearly pure white color with CIE coordinates of (x = 0.34~0.35, y = 0.35~0.37) under applied voltage in the range of 6~10 V. The luminance and quantum efficiency of D5 were $17,160cd/m^2$ and 3.8% at 10 V, respectively.