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有机发光器件(OLED)中的界面研究

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第32卷第1期 2013年1月 中国材料进展 MATERIALS CHINA V0I.32 No.1 Jan.2013 有机发光器件(OLED)中的界面研究 许并社 ,高志翔 ,王 华 ,郝玉英 , (1.太原理工大学新材料界面科学与工程教育部重点实验室,山西太原030024) (2.太原理工大学新材料工程技术研究中心,山西太原030024) (3.太原理工大学物理与光电工程学院,山西太原030024) (4.山西大同大学物理与电子科学学院,山西大同037009) 摘 要:有机电致发光器件由于其成本低、重量轻、低闽值电压、高亮度、无需背光源而自身发 光、宽视角并易于加工等优点成为现代平板显示的研究热点。经过了二十余年的发展,OLED的器 件性能得到大幅度改善。然而,距离实用化还有一定差距,如发光效率低以及器件寿命短等问题, 成为制约其推广应用的技术瓶颈。OLED的器件性能在很大程度上由其器件中的界面结构所决定。 简要介绍OLED中的界面研究进展,围绕金属/有机界面、有机/有机界面、阳极/有机界面以及层 内部材料界面展开叙述,讨论界面结构与OLED器件性能之间的关系,并以多种技术手段和方法研 究OLED界面分子结构、能带结构、激发态特性及反应等获得的主要结果,在此基础上预测OLED 界面研究的发展趋势。 关键词:有机发光器件;界面;磷光材料;发光效率 许并社 中图分类号:TN383 文献标识码:A 文章编号:1674—3962(2013)01—0056—07 Organic Light Emitting Device(OLED)Interface Research XU Bingshe ,GA0 Zhixiang .WANG HHa I' ,HAO Yuying 。 (1.Key Laboratory of Interface Science and Engineering in Advanced Materials. Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,China) (2.Research Center of Advanced Materials Science and Technology.Taivuan University of Technology,Taiyuan 030024,China) (3.The College of Physics and Optoelectronics,Taiyuan University of Technology,Taiyuan 030024,China) (4.School of Physical Science and Electronics.Shanxi Datong University,Datong 037009,China) Abstract:Organic light emitting device(OLED)have been modern flat—panel display research hotspot due to its low cost,lightweight,low threshold voltage,high brightness,no back light sonrce and luminous,wide viewing angle and me— chanical flexibility.After 20 years of development.device performance of organic light emitting device(0LED)has been greatly improved.However,OLED can’t be utilized widely for its rather poor performance.such as low luminous emciency and short 1ire。time.Deviee performance of OLED iS inflnenced】argely by the device interface structure.In the present pa— per,we focused on research progress of metal/organic interface.the organic/organic interface anode/organic interface and the layer of internal material interface in 0LED.discussed the relationship between the interface stuctures and OLED rdevice performance.and the recent research results by a variety of analytical techniques and methods about the interfacial issues of 0LED.such as interfacial molecular structure.energy band.characteristics of excited state and reaction.Final— lv.0LED interface research trends were mentioned. Key words:organic light emitting devices;interfaee;phosphorescent;1uminons efifciency 1 前 言 有机发光器件(Organic Light Emitting Device,OLED) 作为一种新型的平板显示器,具有驱动电压低、响应速 度快、视角大、轻薄美观及可以任意弯曲等特点,展现 出广阔的应用前景。随着OLED技术的发展,OLED的 性能逐步提高,实用化的OLED已经研发出来 。但 OLED仍然存在发光效率较低以及器件寿命较短的问 收稿日期:2O12一O5—24 基金项目:国家自然科学基金(21071108,60976018,21101111);教育 部长江学者与创新团队发展计划项目(IRT0972);国家国 题,成为制约其推广应用的技术瓶颈,如何提高OLED 发光效率和延长器件使用寿命成为目前OLED研究热 点 。已有研究结果表明:OLED的器件性能不仅取 决于OLED所使用材料的性能,而且在很大程度上取决 于OLED界面的物理与化学性质,而器件性能又是由 际合作专项资助(2012DFR50460);山西省自然科学基金 (2010021023—2) 第一作者及通信作者:许并社,男,1955年生,教授 DOI:10.7502/j.issn.1674—3962.2013.01.07 第1期 许并社等:有机发光器件(OLED)中的界面研究 61 Functional Materials,2002(12):245—248. 1ectronic Properties of a Metal/Organic Semiconductor Contact: [7]Sebastian R,Frank L,Schwaaz G,et a1.White Organic Light—E— mitirng Diodes with Fluorescent Tube Eficfiency[J].Nature, 2009(459):234—236. In/Perylenetetracarboxylic Dianhydride[J].Applied Physics Let- ters,1996(68):217—219. 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Emiting Diodes[J].Advanced Materials,2001(13):1 234一 日本首次实现激光操纵磁悬浮石墨烯运动 最近,日本青山学院大学在一项研究中,首次实现了用激光操纵磁悬浮石墨烯运动,通过改变石墨烯的温度, 能改变它的悬浮高度,控制运动方向并让它旋转,而且演示了阳光也能让石墨烯旋转。这一成果对研究光驱动人类 运输工具有重要意义,并有望带来一种新型光能转换系统。相关论文发表在最近出版的《美国化学协会期刊》上。 磁悬浮已证明对从火车到青蛙各种物体都有效,但至今还没有一款磁悬浮的制动器,将外部能量转化为动能。 研究人员解释说,产生磁悬浮是由于物体具有反磁性,会排斥磁场。所有物质都有不同程度的反磁性,通常情况下 反磁性很弱,无法让物体浮起来。只有当物体反磁性的强度超过其顺磁性(被磁场吸引),合磁力为斥力且斥力大于 重力时,才可能浮起。而石墨烯就是反磁性最强的材料之一。 反磁物体的悬浮高度取决于外加磁场和材料本身的反磁性,悬浮位置则可通过改变外加磁场来事先控制。迄今 为止,用外部刺激如温度、光、声音等因素改变材料反磁性,从而控制磁悬浮物体的运动,还没人能做到。 “该研究最重要的一点是实现了实时运动控制技术,首次无需接触而推动一个悬浮着的反磁物体。”论文合著者、 青山学院大学教授安倍次郎(音译)介绍说,“由于该技术简单而且基本,预计它能用于日常生活的许多领域,比如 运输系统、娱乐活动、光照制动器以及光能转换系统等。” 实验中,研究人员演示了用激光控制温度,使一小片磁盘状的石墨烯悬浮在一块钕铁硼(NdFeB)永磁铁的上 方。石墨烯的悬空高度会随着温度升高而下降,反之亦然。研究人员解释说,改变温度会改变石墨烯的磁化率,或 它被外加磁场磁化的程度。在原子尺度,是激光的光热效应增加了石墨烯中热激电子的数量,热激电子越多,石墨 烯的反磁性就越弱,从而悬浮的高度就越低。 把激光瞄准石墨烯盘片中心可以控制高度,瞄准边缘能让它运动和旋转。因为改变温度分布会改变磁化率分 布,使石墨烯在磁场中受到的斥力不均衡,从而沿着与光束运动相同的方向运动。他们设计的旋转装置放在阳光下 也会旋转,转速超过200转/分钟。这对开发光驱动涡轮非常有用。 研究人员预测,放大这种激光控制磁悬浮运动的能力,有望推动磁悬浮制动器、光热太阳能转换系统的发展, 还可用于低成本的环保发电系统、新型光驱运输系统等领域。 (来源:科技日报) 

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