液晶与显示, 2014, 29 (6): 886, 网络出版: 2014-09-15
基于LiF/Al/F4-TCNQ/NPB电荷产生层的叠层有机电致发光器件的特性研究
Characteristic of tandem organic light emitting diodes with charge generation layer of LiF/Al/F4-TCNQ/NPB
摘要
采用结构为LiF/Al/F4-TCNQ/NPB的电荷产生层,制备出了双发光单元叠层有机电致发光器件(OLED: Organic Light Emitting Device)。通过对比实验发现当F4TCNQ层的厚度为8 nm、Al层的厚度为5 nm时,电荷产生层产生电荷的能力较强且具有良好的透光率。基于此,本文制备了发光层为CBP:6%Ir(ppy)3的叠层OLED,通过与单发光单元OLED的性能比较发现: 采用LiF/Al/F4TCNQ/NPB作为电荷产生层制备的叠层OLED的最大电流效率与功率效率分别为516 cd/A、284 lm/W,为单发光单元OLED的216倍、18倍,此外采用这种结构的电荷产生层有效解决了叠层OLED由于工作电压高而导致功率效率并未得到提升的问题[另一方面,采用有机材料F4TCNQ代替传统无机金属氧化物作为电荷产生层中的电荷产生部分,能够避免无机金属氧化物高温升华对Al层薄膜的破坏,提升了器件的效率并且降低了器件的roll-off现象。
Abstract
A novel type of tandem organic light emitting device (OLED) was demonstrated by employing LiF/Al/F4-TCNQ/NPB as charge generation layer (CGL). By contrast experiment, it is suggested that the optimum thickness of F4TCNQ and Al in CGL is 8 nm and 5 nm, respectively, which exhibits the good ability of generating charges and higher optical transmittance.Based on the optimized structure of CGL, we fabricated the tandem OLED with the emission layer of CBP:6%Ir(ppy)3. By comparing the device performance of the tandem OLED and conventional single OLED, it was found that the highest current efficiency and power efficiency were 516 cd/A and 284 lm/W, which was 216 times and 18 times as high as that of single OLED, respectively.In conclusion, the tandem OLED with the CGL of LiF/Al/F4TCNQ/NPB can improve the power efficiency of OLED. In addition, replacing conventional inorganic metal oxide with organic material of F4TCNQ in CGL can avoid the destruction of film formation of Al layer, inducing in improving in performance and weakening the efficiency rolloff phenomenon.
景姝, 王华, 刘慧慧, 杜晓刚, 苗艳勤, 潘成龙, 周禾丰. 基于LiF/Al/F4-TCNQ/NPB电荷产生层的叠层有机电致发光器件的特性研究[J]. 液晶与显示, 2014, 29(6): 886. JING Shu, WANG Hua, LIU Huihui, DU Xiaogang, MIAO Yanqin, PAN Chenglong, ZHOU Hefeng. Characteristic of tandem organic light emitting diodes with charge generation layer of LiF/Al/F4-TCNQ/NPB[J]. Chinese Journal of Liquid Crystals and Displays, 2014, 29(6): 886.