柔性有机薄膜电致发光显示材料及器件

有机薄膜电致发光显示器件(OLED)近年来得到了迅猛发展,是未来全固体平板式彩色显示器的重要候选者,其最大优势之一是可以制作成柔性显示器件。本文综述了柔性有机电致发光材料及器件的发展概况、工作原理与优缺点,目前制作此类器件中存在的困难及解决这些困难的有效措施。     

我国OLED显示配套关键材料技术及产业发展挑战

有机发光二极管（Organic Light-Emitting Diode,OLED）,又称有机电致发光显示器、有机发光半导体。OLED技术由美国柯达公司的邓青云博士在1979年发现,因其具有自发光、无穷高对比度、宽视角、低功耗、响应速度极快、可实现柔性显示等特性,自从发现之后就被视为新一代显示技术。OLED有机材料是OLED显示面板配套关键材料.     

柔性有机发光二极管材料与器件研究进展

有机发光二极管(Organic Light Emitting Diodes,简称OLED)是全固态的薄膜发光器件。由于OLED的可柔性制备、低驱动电压、低功耗等优点,其在未来的可穿戴应用上具有广阔的发展前景。目前,小尺寸的OLED显示器已经实现商业化,大尺寸的OLED电视和照明也已有产品问世,但OLED器件的可穿戴应用尚处于探索期。综述了近年来基于可穿戴应用的柔性OLED材料及器件技术的研究进展,具体介绍了柔性基板材料、柔性薄膜晶体管材料、柔性OLED发光层技术、柔性薄膜封装材料与技术等方面的研究进展。此外,介绍了近几年来兴起的一些新型的柔性器件制备技术,如柔性纤维布基底技术、纤维状聚合物发光电化学池技术、对称平面层器件结构和狭缝涂布式印刷技术等。最后,对柔性OLED材料与器件技术的发展趋势进行了展望。     

印刷OLED显示用发光材料进展

随着有机发光二极管(OLED)在显示领域的广泛应用,面向低成本、大面积的OLED器件制备技术不断涌现.相较于传统真空蒸镀技术,印刷显示技术具有工艺简便、材料利用率高、可制备大面积柔性器件等优势,被认为是下一代显示器件主流制备技术之一.印刷OLED技术是一项综合了材料、器件、工艺、设备等诸多方面的系统工程,是典型的学科交...     

有机发光器件(OLED)中的界面研究

有机电致发光器件由于其成本低、重量轻、低阈值电压、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.     

有机电致发光器件掺杂研究进展

有机电致发光器件(Organic light-emitting device,OLED)因具有成本低、主动发光、驱动电压低、响应速度快、视角宽及可柔性显示等诸多优势,在平板显示及固态照明领域受到广泛关注。但无论是用作显示还是照明,色彩的应用都是不可或缺的。制备不同颜色的发光器件,除可以使用各种颜色的有机材料外,利用荧光或磷光染料掺杂也是重要的方法。同时,这种方法也可以大大提高器件的量子效率。尤其从理论上来说,磷光OLED的内量子效率可以达到100%。从OLED的掺杂原理、荧光掺杂与磷光掺杂等方面阐述了OLED的研究进展。     

OVPD技术在OLED蒸镀装置中的应用

将OVPD(有机气相沉积)技术应用于OLED(有机电致发光显示器件)蒸镀装置中,研制了一台实验设备,并通过实验验证了其可行性和可控性.该技术克服了常规点源蒸发所产生的有机材料利用率低、膜层均匀性差、不适合大基片镀膜等缺点,为OLED量产设备的研制奠定了基础.     

有机电致发光材料的研发现状

有机电致发光器件 (OLED)具有驱动电压低、主动发光等优势 ,在平板显示领域具有极大的应用前景而引起了广泛的关注。与此同时有机电致发光材料的研发也取得了很大的进展。本文介绍了近年来有机电致发光材料 (包括小分子发光材料和聚合物发光材料 )的研发状况     

白光OLED的研究进展

有机电致发光器件(Organic light-emitting device,OLED)具有质轻且薄、视角宽、色彩鲜艳、节能环保、柔性弯曲的独特优点。白光OLED在未来固态照明和平板显示方面展现出了美好的应用前景,成为国内外的研究重点。通过结构设计和器件优化,目前白光OLED的发光效率已经能够达到荧光灯的效率。主要讨论了近年来白光OLED的主要发展,并从发光染料的角度讨论了不同类型白光器件的研究状况。     

有机电致发光器件封装材料的制备研究

针对有机电致发光器件在显示器领域内的蓬勃发展和广泛应用，本论文对有机电致发光器件封装材料的制备进行了分析研究，首先分析介绍了有机电致发光的优点以及常用的封装方法，在此基础上重点探讨了封装材料的制备工艺，给出了防潮等关键技术措施，对于进一步提高有机电致发光器件封装材料的制备工艺水平具有一定借鉴指导意义。     

Amorphous indium tin oxide electrodes for piezoelectric and light-emitting device deposited by vacuum roll to roll process

The amorphous indium tin oxides (ITOs) and the transparent conducting oxides (TCOs) electrode on the flexible polymer substrate, polyvinylidene difluoride (PVDF), and their application to the suggested combinational device system were studied. The lower range ordered crystalline structure of the ITOs enable the reduction of micro-cracks or defect grains under flexible conditions. With the piezoelectric function of substrate polymer, which is added to the display function with OLED (Organic light emitting diodes), the pattern design with the separated electrodes for two devices for emitting light and vibration was considered. From these results, the concept of a combinational flexible electronic device system with a functional polymer substrate could be suggested.     

Biowaste-Derived,Self-Organized Arrays of High-Performance 2D Carbon Emitters for Organic Light-Emitting Diodes

Low-cost flexible organic light-emitting diodes (OLEDs) with nanoemitter material from waste open up new opportunities for sustainable technology. The common emitter materials generated from waste are carbon dots (CDs). However, these have poor luminescent properties. Further solid-state emission quenching makes application in display devices challenging. Here, flexible and rigid OLED devices are demonstrated using self-assembled 2D arrays of CDs derived from waste material, viz., human hair. High-performance CDs with a quantum yield (QY) of 87%, self-assembled into 2D arrays, are achieved by improving the crystallinity and decreasing the CDs' size distribution. The CD island array exhibits ultrahigh hole mobility (≈10⁻¹ cm² V⁻¹ s⁻¹) and significant reduction in solid-state emission quenching compared to pristine CDs; hence, it is used here as an emitting layer in both indium tin oxide (ITO)-coated glass and ITO-coated flexible poly(ethylene terephthalate) (PET) substrate OLED devices, without any hole-injection layer. The flexible OLED device exhibits a stable, voltage-independent blue/cyan emission with a record maximum luminescence of 350 cd m⁻², whereas the OLED device based on the rigid glass substrate shows a maximum luminescence of 700 cd m⁻². This work sets up a platform to develop next-generation OLED displays using CD emitters derived from the biowaste material.     

有机电致发光显示中国专利态势分析

利用Thomson data analyzer及中外专利数据库服务平台等工具,从专利类型分布、专利数量年度分布、国家/地区分布等方面分析了在我国申请的有机电致发光显示专利,特别是从法律状态方面进行了较为深入的分析,揭示了有机电致发光显示技术在我国的整体发展态势。     

Long‐Lived Flexible Displays Employing Efficient and Stable Inverted Organic Light‐Emitting Diodes

Although organic light‐emitting diodes (OLEDs) are promising for use in applications such as in flexible displays, reports of long‐lived flexible OLED‐based devices are limited due to the poor environmental stability of OLEDs. Flexible substrates such as plastic allow ambient oxygen and moisture to permeate into devices, which degrades the alkali metals used for the electron‐injection layer in conventional OLEDs (cOLEDs). Here, the fabrication of a long‐lived flexible display is reported using efficient and stable inverted OLEDs (iOLEDs), in which electrons can be effectively injected without the use of alkali metals. The flexible display employing iOLEDs can emit light for over 1 year with simplified encapsulation, whereas a flexible display employing cOLEDs exhibits almost no luminescence after only 21 d with the same encapsulation. These results demonstrate the great potential of iOLEDs to replace cOLEDs employing alkali metals for use in a wide variety of flexible organic optoelectronic devices.     

Fully printed separated carbon nanotube thin film transistor circuits and its application in organic light emitting diode control

The advantages of printed electronics and semiconducting single-walled carbon nanotubes (SWCNTs) are combined for the first time for display electronics. Conductive silver ink and 98% semiconductive SWCNT solutions are used to print back-gated thin film transistors with high mobility, high on/off ratio, and high current carrying capacity. In addition, with printed polyethylenimine with LiClO4 as the gating material, fully printed top-gated devices have been made to work as excellent current switches for organic light emitting diodes (OLEDs). An OLED driving circuit composed of two top-gated fully printed transistors has been fabricated, and the successful control over external OLED is demonstrated. Our work demonstrates the significant potential of using printed carbon nanotube electronics for display backplane applications.     

The fracture of brittle thin films on compliant substrates in flexible displays

One mechanical issue in flexible organic light emitting displays (OLED) is the fracture of extremely thin brittle conducting transparent oxide films deposited on thin flexible substrates. Understanding the behaviour of these films under flexed condition is essential for designer of flexible OLED. Controlled buckling experiments on the film and substrate have been designed to study the fracture of the films under both tension and compression. Fracture of the film is superficially similar in both tension and compression. However, under tension a channelling crack is formed, while under compression, the film delaminates, buckles and cracks in a tunnelling motion. The fracture toughness of the film and the delamination toughness have been estimated from these experiments. Design to maximise the flexibility of the device is discussed.     

柔板显示技术研究进展

作为下一代显示技术的代表,模拟普通纸张显示效果的柔板显示技术已经成为世界各国研究的焦点.目前,主要包括4种实现柔板显示的技术,分别为电子墨水显示技术(Electronic ink display technology,EID)、柔性电致发光显示技术(Flexible organic light emitting devices display technology,FOLED)、电致变色显示技术(Electrochromic display technology,ECD)和光子墨水显示技术(Photonic ink display technology,PID).每种技术都有各自的特点,在器件制备方面各自都发展到了不同的程度.主要评述了这4种显示技术的研究进展,并对其未来的发展进行了简要的市场分析.     

Thin-type integral imaging method with an organic light emitting diode panel

A thin and lensless two-dimensional (2D) to three-dimensional (3D) convertible display based on integral imaging using an organic light emitting diode (OLED) panel as a direct emissive light source is proposed with improved optical efficiency. A point light source array for 2D-3D convertible display is formed on the surface light source, i.e., the OLED panel. However, a blurring effect and color separation result from the finite (nonzero) size of point light sources since each point light source is generated by a pixel of the OLED panel. Simulation results for a blurring effect and color separation in terms of rays from a light source with finite size is presented. The proposed system has a thin structure and simple convertibility because it does not need any additional optical element to provide 2D-3D convertibility.     

Improving the contrast ratio of OLED displays: An analysis of various techniques

Organic light emitting diode (OLED) based displays have matured into commercial products. However, while we consider OLED for a low-cost high-resolution and high-contrast displays with a long life span, still there are performance gaps. This review addresses various techniques used for increasing the ambient contrast ratio of OLED displays. There are techniques which are integral to the OLED device, such as black cathodes and absorbing transport layers. In contrast, anti-reflection (AR) coatings and circular polarizer are applied externally to the device. This review provides a brief overview of each technique along with a discussion on its merits and demerits. The choice of a particular contrast enhancement technique for a display depends on the ambient where the same is intended to be used. Accordingly, for indoor and outdoor applications, the best possible methods are suggested.