有机发光器件(OLED)封装技术的研究现状分析

有机发光器件(OLED)诞生至今,封装方式一直是提高其寿命和稳定性的重要因素之一,也是当前研究的热点。从最初的后盖式封装发展到现在的薄膜封装,其寿命和稳定性也随之提高,人们幻想的柔性显示也成为了现实。新的有效封装方法的出现使有机发光器件从实验室走进了人们的日常生活,并有望成为下一代显示器的主流。文章重点介绍了当今主要的封装技术和方法,提出了结合传统后盖式封装和薄膜封装的混合封装方法。     

柔性有机电致发光器件的寿命

综述了柔性有机电致发光器件(FOLED)的研究现状和发展趋势;针对提高其寿命问题的研究,选择和比较了聚合物、金属箔片、超薄玻璃3种柔性衬底材料的优缺点及发展概况;结合本课题组的实验分析,说明设计并选择合理的器件结构、发光材料和阴极材料对延长器件的使用寿命非常有效;提高FOLED寿命的另一重要步骤是减少水蒸汽和氧气向器件内部的渗透,最后也简介了以聚合物和超薄玻璃为衬底材料的器件封装方法。     

有机电致发光器件封装技术的研究进展

有机电致发光显示器件(OLED)被认为是最有潜力的平板显示器件之一.由于OLED具有低驱动电压、高亮度、宽视角及超薄等优点,逐渐成为各国研究的热点.OLED对水分和氧气都非常敏感,进入到器件内部的水分和氧气会严重影响器件的寿命,因而影响OLED的产业化发展.OLED器件的有效封装能延长器件的寿命.综述了玻璃衬底、柔性衬底OLED封装技术的研究现状,以及不同封装的优缺点.     

聚对二甲苯类薄膜用于有机电致发光器件的封装

采用热解化学气相沉积聚合(TCVDP)方法制备了聚对二甲苯(PPX)和聚一氯对二甲苯(PCPX)薄膜材料,利用其对有机电敛发光器件(OLED)进行了封装.利州紫外可见光谱、扫描电镜(SEM)对薄膜的相关性能进行了表征.比较了器件经过两种薄膜封装前后器件的工作寿命.实验结果表明:利用TCVDP方法,可以制备出透明的表面平整、结构致密的聚对二甲苯类薄膜材料;用于OLED)的封装能大幅度地提高器件的工作寿命,经过PPX封装后的寿命为1215 h,经过PCPX封装后的寿命为1 558 h,比未封装的器件寿命(197 h)提高了6～8倍.     

柔性OLED封装方法的研究靠

有机电致发光二极管与其他显示器件相比,最大的优势就是可以制备在聚合物基板上,实现柔性显示,但聚合物对水、氧的阻挡能力远不如玻璃.因此,为了延长柔性OLED器件寿命,就要在柔性器件的基板和盖板上制作薄膜阻挡层,进行有效的封装.介绍了OLED的封装方式的进展,并提出了一些柔性OLED的封装方案.     

柔性OLED显示及封装技术的研究

有机发光二极管(OLED)是最具发展潜力的显示技术之一,而器件的使用寿命短的缺点影响了OLED的发展.有机电致发光器件在柔性衬底上的制备是下一代显示技术发展的重要方向.介绍了柔性OLED及封装技术和金属薄片、聚合物基片及超薄玻璃—聚合物系统的特点,OLED器件的有效封装可以延长器件的寿命.     

有机电致发光器件的封装技术

有机电致发光显示器件(OLED)被认为是综合性能最理想、最具发展前景的下一代显示技术之一。但由于其使用寿命太短,制约了OLED显示技术的产业化发展。对OLED进行有效的封装是解决这些问题,进而提高其使用寿命的最直接和最有效的方法。文章综述了OLED显示器件老化的机理及其封装技术(物理法、化学法、复合封装法);分析了各种封装技术对OLED显示器件寿命的影响因素及各自的优缺点。     

MgF2/Se薄膜封装层对OLED性能及寿命的影响

有机电致发光器件(OLEDs)在使用过程中,易受到 空气中水汽、氧气及其它污染物的影响从而导致其工作寿命降低。本文将具有良好光透过率 和热稳定性的MgF₂薄膜与在水汽和氧气中具有良好稳定性的Se薄膜通过真空蒸镀制成复 合薄膜作为OLEDs的封装层,以达到提高器件使用寿命的目的。器件各功能层蒸镀完成后, 保持真空度(3×10－4 Pa)不变,在阴极表面蒸镀MgF₂/Se薄 膜封装层。比较 了绿光OLED器件(器件结构为ITO/CuPc/NPB/Alq₃:C-545T/Alq ₃/LiF/Al)封装前后的亮度-电压-电流密度特性、电致发光光谱及寿命。研究 发现,经过MgF₂/Se封装后,器件的电流密度-电压特性、亮度和发光光谱几乎没 有受到影响,二者的光谱峰都在528 nm处,色坐标(CIE)分别为(0.3555,0.6131)和(0.3560,0.6104),只是起亮电压由3V变为4V;器件的寿命由原来的175h变为300h,提高了1.7倍 。因此,MgF₂/Se薄膜是一种有效的OLEDs无机薄膜封装层。     

基于OLED器件的封装方法研究

有机电致发光二极管(Organic Light-Emitting Diode,OLED)显示因其全固态、自发光、具有高发光效率等优点,市场占有率逐年提高。然而,可靠封装仍然是困扰OLED显示领域的关键技术问题之一。首先从常见的OLED封装方法展开讨论,分析了各种结构特点与缺陷,其次论述了具有广大发展前景的薄膜封装技术封装结构发展历程,以及封装结构的改进。最后对目前常见的无机薄膜制备工艺与有机薄膜制备工艺进行了归纳对比,并对薄膜封装的发展提出了展望。     

有机电致发光器件薄膜封装研究进展

有机电致发光器件(OLEDs)对水汽和氧气非常敏感,渗入OLEDs内的水汽和氧气会腐蚀有机功能层及电极材料,严重影响器件寿命。文中根据OLEDs对封装材料的要求,分析了目前最有前景的OLEDs封装技术———薄膜封装,重点介绍了薄膜封装的分类和研究现状。     

硫系玻璃薄膜封装层对OLED寿命的影响

在高真空条件下(3×10-4Pa),利用硫系玻璃(Se,Te,Sb)薄膜封装材料对有机电致发光器件(OLED)进行原位封装,有效避免了传统封装方法难以避免的水、氧危害,以达到延长器件寿命的目的。实验对比了正常封装与增加Se、Te、Sb薄膜封装层后器件的性能,对比实验中封装过程都未加干燥剂。研究发现Se、Te、Sb薄膜封装层分别可以使器件的寿命延长1.4倍,2倍,1.3倍以上;采用封装层对器件的电流-电压特性、色坐标等光电性能几乎不产生影响,但影响了器件散热,薄膜封装层使器件的击穿电压、最高亮度等参数稍有下降。     

OLED封装技术进展

有机电致发光器件(OLED)因具有较多的优点,在显示领域有着光明的前景,其最大的优越性在于能够实现柔性显示,制作成柔性有机电致发光二极管(FOLED).OLED对水蒸气和氧气非常敏感,渗透进入器件内部的水蒸气和氧气是影响OLED寿命的主要因素,因此,封装技术对器件非常重要.对现有的主要的FOLED衬底材料和封装方法进行...     

A Review on Encapsulation Technology from Organic Light Emitting Diodes to Organic and Perovskite Solar Cells

Organic light emitting diodes (OLEDs) employing organic thin-film based emitters have attracted tremendous attention due to their widespread applications in lighting and as displays in mobile devices and televisions. The novel thin-film photovoltaic techniques using organic or organic–inorganic hybrid materials such as organic photovoltaics (OPVs) and perovskite solar cells (PSCs) have become emerging competitive candidates with regard to the traditional photovoltaic techniques on account of high-efficiency, low-cost, and simple manufacturing processing properties. However, OLEDs, OPVs, and PSCs are vulnerable to the undesired degradation induced by moisture and oxygen. To afford long-term stability, a robust encapsulation technique by employing materials and structures that possess high barrier performance against oxygen and moisture must be explored and employed to protect these devices. Herein, the recent progress on specific encapsulation materials and techniques for three types of devices on the basis of fundamental understanding of device stability is reviewed. First, their degradation mechanisms, as well as, influencing factors are discussed. Then, the encapsulation technologies and materials are classified and discussed. Moreover, the advantages and disadvantages of various encapsulation technologies and materials coupled with their encapsulation applications in different devices are compared. Finally, the ongoing challenges and future perspectives of encapsulation frontier are provided.     

Two-step fabrication of thin film encapsulation using laser assisted chemical vapor deposition and laser assisted plasma enhanced chemical vapor deposition for long-lifetime organic light emitting diodes

A thin film encapsulation layer was fabricated through two-sequential chemical vapor deposition processes for organic light emitting diodes (OLEDs). The fabrication process consists of laser assisted chemical vapor deposition (LACVD) for the first silicon nitride layer and laser assisted plasma enhanced chemical vapor deposition (LAPECVD) for the second silicon nitride layer. While SiN_x thin films fabricated by LAPECVD exhibits remarkable encapsulation characteristics, OLEDs underneath the encapsulation layer risk being damaged during the plasma generation process. In order to prevent damage from the plasma, LACVD was completed prior to the LAPECVD as a buffer layer so that the laser during LACVD did not damage the devices because there was no direct irradiation to the surface. This two-step thin film encapsulation was performed sequentially in one chamber, which reduced the process steps and increased fabrication time. The encapsulation was demonstrated on green phosphorescent OLEDs with I–V-L measurements and a lifetime test. The two-step encapsulation process alleviated the damage on the devices by 19.5% in external quantum efficiency compared to the single layer fabricated by plasma enhanced chemical vapor deposition. The lifetime was increased 3.59 times compared to the device without encapsulation. The composition of the SiNx thin films was analyzed through Fourier-transform infrared spectroscopy (FTIR). While the atomic bond in the layer fabricated by LACVD was too weak to be used in encapsulation, the layer fabricated by the two-step encapsulation did not reveal a Si–O bonding peak but did show a Si–N peak with strong atomic bonding.     

柔性有机电致发光器件的研究进展

柔性OLED技术尚未成熟,要实现产业化,其稳定性和显示效率仍有待进一步改善.本文从FOLED衬底材料的选取和处理、阳极材料的选取和设计、柔性器件的包封等方面,介绍了FOLED几项关键技术研究进展,并对其研究与应用前景进行了展望.     

Suppression of viewing angle dependence of organic light emitting diodes by introduction of circular polarizer with nanoporous polymer film

To improve poor viewing angle characteristics of top emission organic light emitting diodes (TEOLEDs) without any serious pixel blur phenomena, we applied a circular polarizer (CP) film modified by nanoporous polymer film (NPF). From this approach, we could improve the color shift significantly (Δu'v’ in CIE 1976 with viewing angle, from 0.0165 to 0.0114), and expand angular light emission distribution of off-axis by applying CP with NPF. We found that black color shift was little associated with NPF position change although black color was slightly faded tint by applying NPF, as like plasma display panel(PDP)’s off condition. Very interestingly, we found that the reflectance was not changed seriously whether NPF exists between glass encapsulation and CP or not. Besides, we investigated the pixel blur level when we applied different condition in encapsulation thickness and morphology of diffusing films. As a result, we found that the pixel blur phenomena can be significantly suppressed by applying thin encapsulation and NPF type diffuser film.     

Morphology optimization for achieving air stable and high performance organic field effect transistors

To develop an all organic active matrix light emitting display required for large area thin display, electronic paper and electronic paints, Si-based thin film transistor has to be replaced with organic thin film transistor (OTFT). The most important issues in OTFT are the low charge carrier mobility and poor stability under ambient conditions, which critically depend on how organic thin films are grown on different substrates. Here we show that both these issues are correlated and can be overcome by certain surface morphology which can only be achieved through anisotropic growth. Careful control of different growth parameters can lead to unprecedented control on thin film morphology which has been shown to be engineered reversibly and reproducibly. High temperature and low evaporation rate increase the diffusive mobility of molecules, which are responsible for the stacking of molecules to higher length scales. By carefully choosing a temperature and evaporation rate, elongated rod-like grains were grown for achieving high performance and stable thin film transistors.