• Title/Summary/Keyword: Hole injection layer

Search Result 196, Processing Time 0.033 seconds

Study of OLED luminescence efficiency by Hole Transport layer change (유기발광 소자의 수송층 두께 변화에 따른 발광효율 연구)

  • Lee, Jung-Ho
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2004.07b
    • /
    • pp.1002-1006
    • /
    • 2004
  • The studies on OLED(Organic Light-Emitting Diode) materials and structures have been researched in other to improve luminescence efficiency of OLED. Electrons and holes are injected into the devices, transported across the layer and recombine to form excitons, their profiles are sensitive to mobility velocity of electrons and holes. A suggested means of improving the efficiency of LEDs would be to balance the injection of electrons and holes into light emission layer of the device. In this paper, we demonstrate the difference of velocity between hole and electron by experiments, and compare with a data of simulation and experiment changing hole carrier transport layer thickness, so we get the optimal we improve luminescence efficiency. We improve understanding of the various luminescence efficiency through experiments and numerical analysis of luminescence efficiency in the hole carrier transport layer's thicknes.

  • PDF

EL Properties of OLEDs with Different Crystal Structures of Hole Injection Layers of Copper(II)-phthalocyanine (정공 주입층 Copper(II)-phthalocyanine의 결정 변화에 따른 유기발광소자의 발광특성연구)

  • 임은주;이기진;한우미;이정윤;차덕준;이용산;김진태
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.16 no.2
    • /
    • pp.113-119
    • /
    • 2003
  • We report the electrical properties of copper(II)-phthalocyanine(Cu-Pc) as a hole injaction layer in organic light-emitting diode (OLED). OLEDs were constructed by the following material structure : indium tin oxaide (ITO)/ CuPc/ triphenyl-diamine (TPD)/ tris-(8-hydroxyquinoline)aluminum (Alq3)/4-(Dicyanomethlene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM)/ Al. we observed that the change of recombination zone by using a DCM detection thin layer (6 ${\AA}$) in a Alq$_3$ emitting layer. layer. Recombination zone was moved toward the cathode as the hole mobility increased due to the heat-treatment temperature of cupc layer increased.

Synthesis of Conjugated Polymers with Fluorene and Biphenylamine and Application to PLED Devices

  • Park, Eun-Jung;Kwon, Hyeok-Yong;Park, Lee-Soon
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2008.10a
    • /
    • pp.458-460
    • /
    • 2008
  • Four kinds of copolymers with fluorene and biphenylamine units were synthesized by palladium-catalyzed polycondensation reaction. These polymers were characterized in terms of their UV/Visible and photoluminescence (PL) properties in solution and film state. These polymers were also studied as a hole transporting material in the polymer light emitting diode (PLED) devices.

  • PDF

Characteristics on the Variation of Hole transporting layer of Blue organic light-emitting diodes (정공수송층의 변화에 따른 청색 유기 발광 소자의 특성)

  • Kim, Gu-Young;Park, Jung-Hyun;Seo, Ji-Hoon;Lee, Kum-Hee;Yoon, Seung-Soo;Kim, Young-Kwan
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2007.11a
    • /
    • pp.434-435
    • /
    • 2007
  • We have demonstrated the characteristics on the variation of hole transporting layer in blue organic light-emitting diodes (OLEDs) using new blue fluorescent emitter. We fabricated two types of hole transporting layer structures that one is 4,4',4"-Tris(N-(2-naphthyl)-N-phenyl-amino)-triphenylamine (2-TNATA) of $600{\AA}$ as a hole injection layer, N,N'-diphenyl-N,N'- (2-napthyl)-(1,1'-phenyl)-4,4'-diamine (NPB) of $200{\AA}$ as a hole transporting layer and another device is NPB of $500{\AA}$ without the 2-TNATA. The devices without the 2-TNATA showed improved characteristic of the luminance and efficiency.

  • PDF

The Properties of Hole Injection and Transport Layers on Polymer Light Emitting Diode (정공 주입층 및 수송층에 따른 고분자 유기발광다이오드의 특성 연구)

  • Shin, Sang-Baie;Chang, Ho-Jung
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.14 no.4
    • /
    • pp.37-42
    • /
    • 2007
  • We fabricated the polymer light emitting diodes (PLEDs) with ITO/PEDOT:PSS/PVK/PFO:MEH-PPV/LiF/Al structures. The effect of the thickness of PEDOT:PSS hole injection layer(HIL) on the electrical and optical properties of PLEDs was investigated. In addition, PVK hole transport layer(HTL) was introduced in the PLED device, and compared the properties of the PLEDS with and without PVX layer. All organic film layers were prepared by the spin coating method on the plasma treated ITO/glass substrates. As the thickness of PEDOT:PSS film layer decreased from about 80 nm to 50 nm, the luminance of PLED device increased from $220cd/m^2$에서 $450cd/m^2$. This may be ascribed to the increased transportation efficiency of the holes into the emission layer of PLED. The maximum current density and luminance were obtained fir the PLED device with PVX hole transport layer, showing that the current density and luminance were $268mA/cm^2\;and\;540cd/m^2$ at 12V, respectively. This values were improved by about 14% and 22% in current density and luminance compared with the PLED device without PVK layer.

  • PDF

Effect on Electrical Characteristics of OLEDs According to Energy Gap for HIL of Amorphous Fluoropolymer Materials by Simulation (모의시험에서 정공 주입층 물질 AF의 에너지 갭이 OLED의 전기적 특성에 미치는 영향)

  • Han, Hyun-Seok;Kim, Jung-Sik;Kim, Weon-Jong;Lee, Jong-Yong;So, Byung-Mun;Kim, Tae-Wan;Hong, Jin-Woong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2010.06a
    • /
    • pp.33-33
    • /
    • 2010
  • Electrical properties of organic light-emitting diodes (OLEDs) were simulated by S.co's program. The OLEDs have stable operating parameters, high luminance, and high efficiency in simulation. The AF stands for amorphous fluoropolymer in simulation, and it was used as a hole-injection layer. In the five structure of OLEDs, an AF layer is sandwiched between the hole-transport layer and the ITO layer to increase the external quantum efficiency. By considering organic light-emitting diodes using an optimal energy gap of AF, it could contribute to the improvement of the efficiency of the device in the simulation.

  • PDF

Effects of PEDOT:PSS Buffer Layer in a Device Structure of ITO/PEDOT:PSS/TPD/Alq3/Cathode

  • Ahn, Joon-Ho;Lee, Joon-Ung
    • Transactions on Electrical and Electronic Materials
    • /
    • v.6 no.1
    • /
    • pp.25-28
    • /
    • 2005
  • We have investigated the effects of hole-injection buffer layer in organic light-emitting diodes using poly(3,4-ethylenedioxythiophene):poly(stylenesulfonate)(PEDOT:PSS) in a device structure of $ITO/PEDOT:PSS/TPD/Alq_{3}/cathode$. Polymer PEDOT:PSS buffer layer was made by spin casting method. Current-voltage, luminance-voltage characteristics and efficiency of device were measured at room temperature with a variation of cathode materials; Al, LiF/Al, LiAl, and Ca/Al. The device with LiF/Al cathode shows an improvement of external quantum efficiency approximately by a factor of ten compared to that of Al cathode only device. Our observation shows that cathode is important in improving the efficiency of the organic light-emitting diodes.

Electrical Properties of Multi-layer Organo-lanthanide OLEDs (다층구조 Organo-lanthanide OLED의 전기적 특성)

  • Ha, Mi-Young;Kim, So-Youn;Moon, Dae-Gyu
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2006.04a
    • /
    • pp.83-84
    • /
    • 2006
  • ITO/4, 4', 4"-tris (N -3 - methylphenyl - N - phenyl - amino) - triphenylamine, [m-MTDATA] / Terbium Iris - (1 - phenyl - 3 - methyl - 4 - (tertiarybutyryl) - pyrazol - 5 - one) triphenylphosphine oxide [$(tb-PMP)_3Tb-(Ph_3PO)$] / Mg:Ag devices were made to investigate its electrical and light emission properties. The thickness of m-MTOATA layer was varied from 0 to 80 nm. There was a threshold thickness for the sufficient hole injection. The insertion of 20 nm thick m-MTDATA layer between ITO and Tb-complex resulted in the right shift of current-voltage curve because of the insufficient hole injection. The low operating voltage can be obtained above the 40 nm of m-MTDATA layer. The insertion of m-MTDATA induced the increase of the background in the electroluminescence spectrum which was dependent on the current density of the devices.

  • PDF

Polymeric hole-injection layer for high-efficiency and long-lifetime in organic light-emitting diodes

  • Choi, Mi-Ri;Han, Tae-Hee;Woo, Seong-Hoon;Lim, Kyung-Geun;Yun, Won-Min;Kwon, Oh-Kwan;Park, Chan-Eon;Shin, Hoon-Kyu;Hur, Dal-Ho;Shin, Kyoung-Hwan;Jang, Jyong-Sik;Lee, Tae-Woo
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2009.10a
    • /
    • pp.781-783
    • /
    • 2009
  • We achieved high efficiency and long lifetime in small-molecule organic light-emitting diodes using a blend of polyaniline-based conducting polymer and a perfluorinated ionomer as a hole injection layer (HIL). The HIL formed by single spin coating greatly enhanced the surface work function and thus the hole injection from the anode, which resulted in great improvement in device luminous efficiency. We find that the solution processed HIL outperforms the conventional vacuum-deposited small molecule HIL in terms of the device performance.

  • PDF

A Study on New Materials for Organic Active Devices (유기 능동 소자 제작을 위한 신소재 연구)

  • Lee, Sung-Jae;Lim, Sung-Taek;Shin, Dong-Myung;Choi, Jong-Sun;Lee, Hoo-Sung;Kim, Young-Kwan;Sohn, Byoung-Chung
    • Journal of the Korean Applied Science and Technology
    • /
    • v.17 no.3
    • /
    • pp.174-177
    • /
    • 2000
  • The effect of a-sexithiophene(${\alpha}-6T$) layers on the light emitting diode (LED) were studied. The ${\alpha}-6T$ was used for a buffer layer in electroluminescent (EL) devices. Enhanced carrier (hole) injection and improved emission efficiency were observed. Carrier injection characteristics were investigated as a function of ${\alpha}-6T$ later thickness. The efficiency of the electroluminescence was proportional to the thickness of ${\alpha}-6T$ layer. The highest efficiency was observed 600A of ${\alpha}-6T$ later, which was about 1.5 times higher than that of device without ${\alpha}-6T$ later. The device with a-6T showed an operation voltage lowered by 2V. The ${\alpha}-6T$ layer can substitute hole blocking layer, and control charge injection properties.