【作者】 孙媛媛；

【导师】 华玉林；

【作者基本信息】 天津理工大学 ， 凝聚态物理， 2005， 硕士

【摘要】 目前,国内外一般OLED器件的制作是以刚性的不可弯曲的ITO导电玻璃作为衬底,此类器件虽有较优良的发光性能,但由于以玻璃为衬底其抗震动,抗冲击的能力较弱,器件也相对较重,其应用会受到很大的限制。而FOLED器件则是以柔韧性好,且具有良好透光性的材料代替玻璃作为衬底制成器件,因而具有一些明显的优点,故发展FOLED器件具有特殊的意义。因此我们针对此类器件做了如下几方面的工作:1.首先选用Alq₃作为发光材料,PVK:TPD为空穴传输材料,分别制备了结构为a:PET/ITO/PVK:TPD/Alq₃/Al和b:玻璃/ITO/PVK:TPD/Alq₃/Al的器件,FOLED器件在20V电压驱动下,亮度为1000cd/m2,量子效率达到0.27%。玻璃衬底OLED器件20V电压驱动下,亮度为1200cd/m2,量子效率达到0.29%。对两种器件的光电性能进行比较分析可知FOLED器件的各种光电性能与玻璃衬底OLED器件非常相似。分析了FOLED器件光电性能略差于玻璃衬底OLED器件的原因,通过此实验摸索出了制备FOLED器件的基本条件。2.选择一种较新型电致发光材料Zn（BTZ）₂,制备了DL-A型双层结构器件:PET/ITO/PVK:TPD/Zn（BTZ）₂/Al,25V驱动时亮度值达1000cd/m2,量子效率值为0.25 %,但其色坐标基本为（x=0.242,y=0.359）已位于白场之内。3.将荧光染料Rubrene掺入到Zn（BTZ）₂电致发光器件发光层之中,制备了不同掺杂浓度比电致发光器件,器件结构为:PET/ITO/PVK:TPD/Zn（BTZ）₂:Rubrene/Al,通过相应的EL光谱图及色坐标值,确定了实现纯白色电致发光时,Zn（BTZ）₂:Rubrene的最佳掺杂浓度比为0.05%,从而得到了色坐标值为（x=0.339,y=0.339）,量子效率值为0.35 %,亮度值达1200cd/m2的纯白色明亮电致发光;并且此掺杂型白光器件色坐标随外加驱动电压在很大变化范围内（10-25V）的变化很小,均非常接近于白色等能点。讨论了Rubrene的掺杂机制问题,并详细分析和研究了掺杂剂Rubrene对Zn（BTZ）₂电致发光器件各项光电性能产生影响的原因,提出在Zn（BTZ）₂和Rubrene之间存在很强的能量传递,并从电荷转移和能带结构两方面解释了产生这种能量转移的原因。4.对器件的抗弯折性能进行了测试,实验表明,制作的FOLED器件基本实现了柔性显示。采用三种不同的封装材料对器件进行了简单的封装,并比较了这三种封装器件的工作寿命和保存寿命的差异。经实验证明经过封装的器件无论是哪种封装方法都使器件的工作寿命和保存寿命都有了一定的提高,虽然还远远低于商品化标准,但已经有了明显的改善,封装效果最好的器件比未封装器件的工作寿命已提高了10倍,保存寿命提高了6倍。此外还尝试采用Mg:Ag合金做阴极替代了原有的Al阴极,使器件的性能有了一定提高。5.展望FOLED显示器件的未来发展,我们在FOLED器件制备工艺方面还有很多需要改进的地方,如寿命问题,虽然将器件进行简单的封装后寿命有所改善,但依然远远低于商品化的要求,因此要进一步摸索出适合FOLED器件的封装技术,提高器件的寿命。更多还原

【Abstract】 Organic light emitting devices （OLED） has gained a rapid development recently. It is technically crucial in the field of plate panel displays in the future. However, most of white OLEDs, so far, are fabricated with multilayer structures, which results in the complication of fabrication process and decline of quantum efficiency. So these devices are not suitable for the purpose of large-scale industrial manufacture. But the most important superiority of OLED is that it can realize flexible displays—flexible organic light emitting devices（FOLED）.In this paper, firstly, FOLED with ITO/PVK:TPD/Alq₃/Al configuration prepared on PET substrates were fabricated. The curves of the Current density-Voltage, Optical current-Voltage and Quantum efficiency-Current density of the devices were investigated. Compared to those with glass substrates fabricated under the same conditions, the opening voltage of the FOLED was a little higher than them, but those characteristics of two kinds of devices were very similar. Under the driving voltage of 20V, the corresponding brightness and quantum efficiency were 1000cd/m² and 0.27%.Bis-2-（2-hydroxyphenyl）benzothiazolate)zinc （Zn（BTZ）₂） is one of the best white electro- luminescent materials used OLED. In this paper, PET slice coated with ITO was used as substrate of FOLED. We used Zn（BTZ）₂ as main light-emitting material and fabricated a new type of flexible organic white-light-emitting devices. The configurations of the devices were as follows: PET/ITO/PVK:TPD/Zn（BTZ）₂/Al. The bright and steady light emitting had been obtained, and the brightness of the devices came to 1000cd/m2 （at a driving voltage of 25V）. We also measured the CIE coordinates of the above devices, which were （x = 0.242, y = 0.359）, and corresponding quantum efficiency value was 0.25%. Then the Rubrene was doped in Zn（BTZ）₂（doping rate 0.05%）, and the configurations of this devices were as follows: ITO/PVK:TPD /Zn（BTZ）₂:Rubrene /Al. The brightness of the devices came to 1200cd/m2 （at a driving voltage of 25V）, and the CIE coordinates of the above devices were（x = 0.339, y = 0.339）, and corresponding quantum efficiency value was 0.35%. we also discussed the emitting mechanism of the material and the devices.Besides those, we also discussed the luminescence mechanisms and the capability of the devices curved. The reasons which caused the failure of the devices were analyzed. Lastly, three kinds of encapsulated material were used to envelop FOLED, and the lifetime of three kinds devices was studied and compared. Although lifetime of our enveloped devices was far less than commercial standard, it had made a remarkable progress. And then , the alloy Mg:Ag was used to substitute the Al anode, which improved the performances of FOLED. We believe the commercial OLED is not far away from us.更多还原