• Title, Summary, Keyword: Transport Layer

검색결과 1,163건 처리시간 0.053초

HTL:EML(DPVBi:NPB) 층의 조성비 변화에 따른 청색 유기 발광 소자 개발 (Development of Blue Organic Light-Emitting Diodes(OLEDs) Due to Change in Mixed Ratio of HTL:EML(DPVBi:NPB) Layers)

  • 이태성;이병욱;홍진수;김창교
    • 한국전기전자재료학회:학술대회논문집
    • /
    • /
    • pp.31-32
    • /
    • 2008
  • The structure of OLEDs with conventional heterostructure consists of anode, hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer, and cathode. NPB used as a hole transport layer and DPVBi used as a blue light emitting layer were graded-mixed at selected ratio. Interface at heterojunction between the hole transport layer and the elecrtron transport layer restricts device's stability. Mixing of the hole transport layerand the emitting layer removes abrupt interface between the hole transport. layer and the electron transport layer. The stability of OLED with graded mixed-layer developed in this study was improved.

  • PDF

The Study of Luminescence Efficiency by change of OLED's Hole Transport Layer

  • Lee, Jung-Ho
    • International Journal of Precision Engineering and Manufacturing
    • /
    • v.7 no.2
    • /
    • pp.52-55
    • /
    • 2006
  • The OLEDs(Organic Light-Emitting Diodes) structure organizes the bottom layer using glass, ITO(indium thin oxide), hole injection layer, hole transport layer, emitting material layer, electron transport layer, electron injection layer and cathode using metal. OLED has various advantages. OLEDs research has been divided into structural side and emitting material side. The amount of emitting light and luminescence efficiency has been improved by continuing effort for emitting material layer. The emitting light mechanism of OLEDs consists of electrons and holes injected from cathode and anode recombination in emitting material layer. The mobilities of injected electrons and holes are different. The mobility of holes is faster than that of electrons. In order to get high luminescence efficiency by recombine electrons and holes, the balance of their mobility must be set. The more complex thin film structure of OLED becomes, the more understanding about physical phenomenon in each interface is needed. This paper observed what the thickness change of hole transport layer has an affection through the below experiments. Moreover, this paper uses numerical analysis about carrier transport layer thickness change on the basis of these experimental results that agree with simulation results.

HTL:EML(DPVBi:NPB)층의 조성비 변화에 따른 청색 유기 발광 소자 개발 (Development of Blue Organic Light-emitting Diodes(OLEDs) Due to Change in Mixed Ratio of HTL:EML(DPVBi:NPB) Layers)

  • 이태성;이병욱;홍진수;김창교
    • 한국전기전자재료학회논문지
    • /
    • v.21 no.9
    • /
    • pp.853-858
    • /
    • 2008
  • The structure of organic light-emitting diodes(OLEDs) with typical heterostructure consists of anode, hole injection layer, hole transport layer, light-emitting layer, electron transport layer, electron injection layer, and cathode. 4,4bis[N-(1-napthyl)-N-phenyl-amino]-biphenyl(NPB) used as a hole transport layer and 4'4-bis(2,2'-diphenyl vinyl)-1,1'-biphenyl(DPVBi) used as a blue light emitting layer were graded-mixed at selected ratio. Interface at heterojunction between the hole transport layer and the elecrtron transport layer restricts carrier's transfer. Mixing of the hole transport layer and the emitting layer reduces abrupt interface between the hole transport layer and the electron transport layer. The operating voltage of OLED devices with graded mixed-layer structure is 2.8 V at 1 $cd/m^2$ which is significantly lower than that of OLED device with typical heterostructure. The luminance of OLED devices with graded mixed-layer structure is 21,000 $cd/m^2$ , which is much higher than that of OLED device with typical heterostructure. This indicates that the graded mixed-layer enhances the movement of carriers by reducing the discontinuity of highest occupied molecular orbital(HOMO) of the interface between hole transport layer and emitting layer.

트랜스포트 계층과 네트워크 계층 이동성 관리 방안들의 성능비고 (Performance Comparison of Transport vs. Network Layer Mobility Management Mechanisms)

  • 장문정;이미정
    • 한국정보과학회논문지:정보통신
    • /
    • v.33 no.1
    • /
    • pp.28-37
    • /
    • 2006
  • 최근 새로운 트랜스포트 계층 프로토콜인 SCTP를 기반으로 한 트랜스포트 계층 이동성 지원방안이 제안되었다. 본 논문에서는 이들 트랜스포트 계층 이동성 지원 방안이 지금까지 제안되어 온 대표적인 IPv6 기반 네트워크 계층에서의 이동성 지원 방안들에 비하여 어느 정도의 성능을 보이는지 그 위치를 가늠해 보고, 이들 각 프로토콜이 수반하는 오버헤드를 비교하였다 시뮬레이션 결과를 통하여 트랜스포트 계층에서의 종단 간 이동성 지원 방안이 네트워크 계층 이동성 지원 방안들이 수반하는 오버헤드보다 더 낮은 오버헤드를 가지며 전송 성능이나 핸드오버 지연 측면에서 MIPv6와 유사하거나 더 좋은 성능을 보임을 알 수 있었다.

The effect of fullerene on the device performance of organic light-emitting

  • Lee, Jun-Yeob
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • /
    • pp.1805-1808
    • /
    • 2006
  • In this paper, we describe a versatile use of fullerene(C60) as a charge transporting material for organic light-emitting diodes. The use of fullerene as a buffer layer for an anode, a doping material for hole transport layer, and an electron transport layer was investigated. Fullerene improved the hole injection from an anode to a hole transport layer by lowering the interfacial energy barrier and enhanced the lifetime of the device as a doping material for a hole transport layer. In addition, it was also effective as an electron transporting material to get low driving voltage in the device.

  • PDF

BCP 전자수송층 두께가 백색 OLED의 효율 및 발광 특성에 미치는 영향 (Effects of BCP Electron Transport Layer Thickness on the Efficiency and Emission Characteristics of White Organic Light-Emitting Diodes)

  • 서유석;문대규
    • 한국전기전자재료학회논문지
    • /
    • v.27 no.1
    • /
    • pp.45-49
    • /
    • 2014
  • We have fabricated white organic light-emitting diodes (OLEDs) using several thicknesses of electron-transport layer. The multi-emission layer structure doped with red and blue phosphorescent guest emitters was used for achieving white emission. 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) was used as an electron-transport layer. The thickness of BCP layer was varied to be 20, 55, and 120 nm. The current efficiency, emission and recombination characteristics of multi-layer white OLEDs were investigated. The BCP layer thickness variation results in the shift of emission spectrum due to the recombination zone shift. As the BCP layer thickness increases, the recombination zone shifts toward the electron-transport layer/emission-layer interface. The white OLED with a 55 nm thick BCP layer exhibited a maximum current efficiency of 40.9 cd/A.

Performance Comparison of CuPc, Tetracene, Pentacene-based Photovoltaic Cells with PIN Structures

  • Hwang, Jong-Won;Kang, Yong-Su;Park, Seong-Hui;Lee, Hye-Hyun;Jo, Young-Ran;Choe, Young-Son
    • 한국진공학회:학술대회논문집
    • /
    • /
    • pp.311-312
    • /
    • 2010
  • The fabricated photovoltaic cells based on PIN heterojunctions, in this study, have a structure of ITO/poly(3, 4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)/donor/donor:C60(10nm)/C60(35nm)/2, 9-dimethyl-4, 7-diphenyl-1, 10-phenanthroline(8nm)/Al(100nm). The thicknesses of an active layer(donor:C60), an electron transport layer(C60), and hole/exciton blocking layer(BCP) were fixed in the organic photovoltaic cells. We investigated the performance characteristics of the PIN organic photovoltaic cells with copper phthalocyanine(CuPc), tetracene and pentacene as a hole transport layer. Discussion on the photovoltaic cells with CuPc, tetracene and pentacene as a hole transport layer is focussed on the dependency of the power conversion efficiency on the deposition rate and thickness of hole transport layer. The device performance characteristics are elucidated from open-circuit-voltage(Voc), short-circuit-current(Jsc), fill factor(FF), and power conversion efficiency($\eta$). As the deposition rate of donor is reduced, the power conversion efficiency is enhanced by increased short-circuit-current(Jsc). The CuPc-based PIN photovoltaic cell has the limited dependency of power conversion efficiency on the thickness of hole transport layer because of relatively short exciton diffusion length. The photovoltaic cell using tetracene as a hole transport layer, which has relatively long diffusion length, has low efficiency. The maximum power conversion efficiencies of CuPc, tetracene, and pentacene-based photovoltaic cells with optimized deposition rate and thickness of hole transport layer have been achieved to 1.63%, 1.33% and 2.15%, respectively. The photovoltaic cell using pentacene as a hole transport layer showed the highest efficiency because of dramatically enhanced Jsc due to long diffusion length and strong thickness dependence.

  • PDF

P3HT를 이용한 다층막 전계발광 소자의 전기-광학적 특성 (The Electro-optical Properties of Multilayer EL Devices with P3HT as Emitting layer)

  • 김대중;김주승;김정호;구할본
    • 한국전기전자재료학회:학술대회논문집
    • /
    • /
    • pp.1018-1021
    • /
    • 2003
  • We have synthesized poly(3-hexylthiophene) and studied the optical properties of P3HT for applying to the red emitting materials of organic electroluminescent device. Usually, an organic EL device is composed of single layer like anode/emitting layer/cathode, but additional layer such as hole transport, electron transport and buffer layer is deposited to improve device efficiency. In this study, Multilayer EL devices were fabricated using tris(8-hydroxyquinolinate) aluminum($Alq_3$) as electron transport material, (N,N'-diphenyl-N,,N'(3-methylphenyl)-1,1'-biphenyl-4,4'diamine))(TPD) as hole transport/electron blocking materials and LiF as buffer layer. That is, a device structure of ITO/blending layer(TPD+P3HT)/$Alq_3$/LiF/Al was employed. In the Multilayer device, the luminance of $10{\mu}W/cm^2$ obtained at 10V. And, we present the experimental evidence of the enhancement of the Foster energy transfer interaction in emitting layer.

  • PDF

다층 고온 초전도 케이블의 전류 분포 및 교류손실 해석 (Current Distribution and Numerical Analysis of AC Losses on Multi-Layer HTS Cable)

  • 김영석;이병성;장현만;곽민환;김상현
    • 한국전기전자재료학회:학술대회논문집
    • /
    • /
    • pp.452-455
    • /
    • 2000
  • Superconducting power cable is one of the most promising energy application of high-T$_{c}$ superconductors (HTS). A prototype HTS cable have been constructed multi-layer cable using Bi-2223 tape and tested. The AC transport losses under self field were investigated at 77K on the 19 filamentary tape and multi-layer HTS cables. And we carried out numerical analysis using bean model. The result shows that the total transport current of HTS cable in L$N_2$ was 475[A], and transport current passed through almost the outer layer (2-layer). Also, AC transport losses in outer layer of HTS cable was proportion to I$^2$ and higher than losses of inner layer. In case of Ip=Ic, calculated numerical loss density was concentrated on the edge of tape and most of loss density in cable was distributed outer layer more than inner layer. As magnetic distribution was concentrated on outer layer.r.

  • PDF

New ETL 층에 의한 저전압 구동 백색 발광 OLED (Low voltage driving white OLED with new electron transport layer)

  • 김태용;서원규;문대규
    • 한국전기전자재료학회:학술대회논문집
    • /
    • /
    • pp.100-101
    • /
    • 2008
  • We have developed low voltage driving white organic light emitting diode with new electron transport layer. The with light emission was realized with a yellow dopant, rubrene and blue-emitting DPVBi layer. The new electron transport layer results in very high current density at low voltage, causing a reduction of driving voltage. The device with new electron transport layer shows a brightness of 1000 cd/m2 at 4.3 V.

  • PDF