【作者】 赵明；

【导师】 王红波；

【作者基本信息】 吉林大学 ， 工程硕士（专业学位）， 2018， 硕士

【摘要】 有机电致发光器件(OLED)以其色饱和度高、能耗低、无需背光源、柔性显示等优势逐渐在显示和照明领域崭露头角。随着产业化规模的提高,我们已经可以在市面上看到越来越多的以OLED作为显示面板的产品。然而对于OLED而言目前仍然存在着许多问题。例如由于磷光材料的三线态激子寿命较长,导致器件发光效率会随着电压升高而产生滚降。由于电子和空穴的传输不平衡,导致器件的色稳定性不佳等。这都是需要在进一步的研究中解决的问题。为了进一步减少OLED的制造成本,简化器件结构是一个重要的方式。我们首先采用双母体结构,利用改变超薄层位置的方式探究了双母体结构的激子主要复合区域。发现双母体结构的激子主要复合区域位于靠近阴极的位置。而后我们在此结构中在双母体结构中掺入了蓝色磷光材料,实现了高效且色稳定较好的白光发射。器件实现了14990 cd/m~2的亮度和3.21 V的低开启电压。其效率达到25.2 cd/A和19.2 lm/W并拥有较好的色稳定性。高效的性能源于双母体结构的采用,使得在母体中空穴和电子都可以分别进行传输,减少了载流子的堆积,并且使得载流子在传输过程中比较平衡,这样可以进一步增强空穴和电子的复合效果,提升器件效率和色稳定性。而使用无掺杂的超薄层结构也起到了简化器件结构的作用。在此基础上,我们利用设计了双发光层结构的白光器件,并在两个发光层之间插入了一个蓝色磷光超薄层,通过改变超薄层的厚度探究磷光材料对器件性能的影响。我们发现超薄层的插入对载流子的传输起到了阻碍作用,降低了器件的发光性能。而没插入超薄层的器件实现了51720 cd/m~2的亮度以及46.7 cd/A(37.9lm/W)的效率。这是由于在发光层中使用双母体结构使得注入的空穴不但能够进入蓝光层,同时也能顺利进入黄光层;而注入的电子同样不但能够进入黄光层,也能顺利进入蓝光层,使得两个发光层都能够顺利的发光。更多还原

【Abstract】 Organic light-emitting diodes(OLED)have gradually emerged in the field of display and lighting due to their high color saturation,low energy consumption,no backlight,flexible display and other advantages.With the increase of the scale of industrialization,we can already see more and more OLED display panel products on the market.However,for OLED,there are still many problems.For example,the long lifetime of triplet excitons in phosphorescent materials leads to the serious roll-off of the efficiency with the increasing voltage.Due to the unbalanced transmission of electrons and holes,the color stability of devices is poor.This problems need to be solved in further research.In order to further reduce the manufacturing cost of OLED,it is important to simplify the device structure.We first investigate the exciton recombination region of the mixed host structure by changing the position of the ultrathin layer.It is found that the main compound region of exciton with mixed host structure is located near the cathode.Then blue phosphorescent materials are doped into the mixed host structure to achieve white emission with high efficiency and good color stability.The device achieves a brightness of 14990 cd/m~2and a low opening voltage of 3.21 V.The efficiency is 25.2cd/A(19.2 lm/W)and good color stability is achieved.High performance is due to the employment of mixed host,which can transport both holes and electrons efficiently,reducing the accumulation of carriers,and making the carrier in the transmission process more balanced,which can further enhance the hole and electrons recombination effect,improve device efficiency and color stability.The use of undoped ultrathin layer structure also plays a role in simplifying the device structure.On this basis,we designed white emitting devices with double emission layers,and inserted a blue phosphorescent ultrathin layer between the two emission layers.By changing the thickness of the ultrathin layer,we explored the influence of phosphorescent materials on the device performance.We found that the insertion of ultrathin layer hindered the carrier transmission and reduced the performance of the device.The device without ultra-thin layer achieves brightness of 51720 cd/m2 and efficiency of 46.7 cd/A(37.9 lm/W).This is due to the use of mixed host structure in the emission layer,the injected holes can not only enter the blue emission layer,but also into the orange emission layer smoothly;and the injected electrons can not only enter the orange emission layer,but also smoothly into the blue emission layer,so that both emission layers can be luminescent efficiently.更多还原