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    Diodos orgánicos emisores de luz (oleds) y sus bases tecnológicas Organic Light Emitting Diodes (OLEDs) and their technological bases
    Julián MoraÓscar GélvezJaime CastroDiego RoaSebastián Flórez
    Main concepts about Organic Light Emitting Diodes (OLEDs) are discussed. A short explanation about the basic structure and mechanisms inside an OLED as a photon emission organic device is given and a review of different types of OLEDs is presented; finally an explanation about different basic OLEDs display configurations, including last advances in OLEDs technologies, is shown.
    Citations (0)
    Fundamental Principle and Progrees in Organic Light Emitting Diode (OLED)
    Yao Huawen
    The development history, structure, working characteristics, methods of getting color display of OLED and its advantages/disadvantages, developing situation and trend have been reviewed. The performances of low molecular OLED and high molecular PLED, OLED and LCD have been compared in detail. Particularly the display principle of OLED was described in detail. Moreover, the structure of passive driving circuit and active driving circuit were summarized, and it is considered that the active driving OLED would be the terminal results. Finally, the development status of OLED both at home and abroad is described.
    Citations (1)
    Synthesis and structure of organotin complexes of ytterbium
    Journal of Organometallic Chemistry (1992)
    Л. Н. БочкаревOleg V. GrachevSergey F. ZiltsovL.N. ZakharovYury T. Struchkov
    Ytterbium
    Chlorine atom
    Citations (28)
    Ytterbium: Effect of Pressure and Temperature on Resistance
    Science (1963)
    R. A. StagerH. G. Drickamer
    The electrical resistance of ytterbium, measured as a function of pressure, shows a sharp maximum at 38 kb, both at 300°K and 77°K. At low pressures ytterbium is a metal because of overlap between filled and empty bands. From about 20 kb to the resistance maximum it is a semiconductor, indicating that the overlap disappears. At the maximum there is a phase transition, and beyond this pressure ytterbium is again metallic.
    Ytterbium
    Citations (6)
    The Effect of Hole-Injection Layers in Single and Double Stack Organic Light-Emitting Diodes
    황주현
    유기발광다이오드 (Organic light-emitting diode - OLED)는 차세대 디스플레이와 고체조명 (Solid-state lighting – SSL)의 후보로 최근 각광받고 있다. 특히 저전력, 고효율, 장수명의 백색 OLED를 제작하는 것은 조명용으로의 OLED에서 필수적인 조건이므로 많은 연구그룹들에게 있어서 해결해야 할 중요한 문제로 자리잡고 있다. 수명과 효율을 증가시키고 구동전류를 감소시켜 안정적인 백색 OLED를 구현하기 위한 한 가지 접근방법은 소자 내의 정공주입층 (Hole-injection Layer - HIL)을 최적화하는 방식이다. 본 논문에서는 정공주입층에 초점을 맞추어 연구를 진행하였다. 먼저 단층과 복층 녹색 형광 OLED 소자를 MoO3를 정공주입층으로 도입하여 적층 녹색 OLED소자의 구동과 효율향상을 IVL과 EL 측정을 통하여 확인하였다. 나아가 MoO3 대신 직접 제작한 고분자 정공주입층인 PEDOT:PSS:PFI을 적용하여 효율의 증가를 확인할 수 있었다. 이처럼 향상된 정공주입능력과 효율은 이 고분자 블렌드를 스핀코팅할 때, PFI 층이 표면 쪽으로 자기정렬되어 표면의 일함수를 대폭 증가시키며 전자의 정공주입층으로의 주입을 막아주기 때문으로 해석할 수 있다. 고분자블렌드 정공주입층을 사용하여 제작한 단층과 복층 OLED소자를 비교하였을 때 효율은 약 1.2 ~ 1.4배 증가하는 경향을 보였다. C-V 측정을 통하여 분석한 결과 위쪽 발광층과 아랫쪽 발광층 사이의 전하 불균형에 의한 것으로 나타났다. 이 결과는 고분자 정공주입층의 변화를 통하여 전하균형을 맞춘다면 용액공정을 적층 OLED에 적용할 수 있는 가능성을 보여주었다. 또한, 본 논문에서는 MoO3를 NPB에 도핑하거나 MoO3와 NPB를 반복적으로 증착하는 방식으로 정공주입/정공전달 혼합층을 두꺼운 두께로 적용하여 녹색 형광 OLED를 구현해보았다. MoO3 도핑된 NPB는 균일하게 분산된 MoO3에 의한 층 내부의 결함과 불순물 등으로 인하여 성능의 향상을 확인할 수 없었다. 그러나 MoO3/ NPB의 반복증착을 구현한 소자에서는 두꺼운 층으로 인한 구동전류감소와 MoO3/NPB의 면적 증가에 따른 정공주입향상 등으로 인해 약 1.2배의 효율과 1.3배의 수명증가를 이루어냈다. 이 결과는 정공주입/정공전달 혼합층으로 이루어진 소자구조에서의 장수명 OLED 구현에 대한 가능성을 나타낸다는 점에서 의미 있는 결과이다.
    Citations (0)
    Low-temperature magnetic properties of the metallic FCC phase of ytterbium
    Journal of Physics F Metal Physics (1978)
    M. RibaultA. Benoı̂tJ. FlouquetG. Chouteau
    In nuclear orientation experiments performed on 3d radioactive ions of 54Mn, 51Cr and 60Co dissolved in FCC ytterbium, the occurrence of the 3d magnetism is exactly that found for divalent matrices. At 4.2K the magnetisation of pure ytterbium varies linearly up to 130 kG. These measurements are in agreement with the existence, in a divalent matrix, of localised Yb3+ condensed at low temperature in a Kondo state. The authors discuss the possible origin of these Yb3+.
    Ytterbium
    Divalent
    Magnetism
    Matrix (chemical analysis)
    Citations (4)
    Advanced Organic Light-Emitting Devices for Enhancing Display Performances
    Journal of Display Technology (2005)
    Chia-Hsin WuC.-W. ChenChun‐Liang LinC.-J. Yang
    Various advanced organic light-emitting devices (OLEDs) for enhancing performances of OLED displays, particularly active-matrix OLED displays, are reviewed in this paper. These include top-emitting OLEDs, inverted OLEDs, high-contrast OLEDs, microcavity OLEDs, and their combinations. How these device structures enhance display performances, such as color saturation, brightness or emission efficiency, contrast, and aperture ratio of pixels, etc., are discussed. The critical technical issues and the status of development associated with each device technology are reviewed.
    Citations (140)
    Research Trends in Organic Light Emitting Diode
    Applied Chemistry for Engineering (2015)
    Hwangyu ShinSeung‐Ho KimJae‐Hyun LeeHayoon LeeHyocheol Jung
    유기 발광 다이오드(OLED)는 학문 및 산업분야에서 많은 관심을 받아 왔으며, 소자가 갖는 우수한 장점을 바탕으로 모바일 디스플레이뿐만 아니라 대면적 TV, 차세대 굴곡형 디스플레이의 적용이 활발하게 진행되고 있다. 또한 OLED 재료의 연구와 소자제작 기술의 응용 연구 범위를 넓혀가고 있다. 본 논문에서는 이러한 OLED에 대한 기본적인 소자구성 및 원리를 설명하고, 다양한 화학구조를 응용한 OLED 재료를 각각의 용도에 맞게 분류 정리하였다. 이러한 OLED 기술의 개념과 재료의 특성을 체계적으로 분류함으로써 새로운 발광 재료를 연구하고 개발함에 있어서 많은 도움이 되리라고 생각한다. Organic Light Emitting Diodes (OLEDs) have been receiving great attention in academic and industrial fields, and it is being actively applied to mobile display, as well as large area TV and next-generation flexible display due to their excellent advantages. In addition, the scope of research on OLED materials and device fabrication technology is getting expanded. This review discusses the principle and basic composition of OLED and also classifies OLED materials with different chemical structures according to their usages. Systematic classification of OLEDs by technical concept and material characteristics can help developing new emitting materials.
    Scope (computer science)
    Citations (2)
    A near-IR luminescent ratiometric ytterbium pH probe
    Dalton Transactions (2019)
    Sergey ShuvaevDavid Parker
    The hypersensitive 2F5/2 to 2F7/2 transition of Yb3+ can be used to monitor perturbations of the coordination sphere in ytterbium(iii) complexes. An envelope of Stark components gives rise to a relatively broad and asymmetric emission band, whilst changes in their relative intensity and energy enable a ratiometric response. We report a new ytterbium complex with a sulphonamide arm that binds reversibly to Yb3+ as a function of pH, giving rise to significant pH dependent changes in the Yb emission spectrum.
    Ytterbium
    Coordination sphere
    Envelope (radar)
    Citations (16)
    Wavelengths, intensities, and Zeeman patterns in ytterbium spectra (Yb I, II, III, IV)
    Journal of Research of the National Bureau of Standards Section A Physics and Chemistry (1966)
    William F. MeggersCharles Corliss
    In 1937, Meggers and Scribner published a paper on arc and spark spectra of ytterbium providing wavelengths, relative intensities, and spectrum numbers of 1668 spectral lines, including about 400 for Yb I, 1250 for Yb II, and 12 for Yb III. That work was handicapped by impure materials and conventional light sources. When pure ytterbium metal and new light sources became available in 1950, Meggers and Corliss decided to make a new description of ytterbium spectra. This new description includes data for 7300 spectral lines with wavelengths between 2000 Å and 12000 Å distributed as follows: 1800 belong to Yb I, 5100 to Yb II, 430 to Yb III, and 5 to Yb IV. The Zeeman effect on 1300 lines has been observed in magnetic field intensities ranging from 3.7 to 9.358 tesla (37000 to 93580 gauss). These data were obtained for chemical identifications and for structural analyses of the first two spectra of ytterbium.
    Ytterbium
    Citations (27)