白光有机电致发光器件发光稳定性研究

Research of high stability white organic light-emitting diodes

基于红绿/蓝双发光层,制作了结构为ITO/MoO3(10nm)/NPB(40nm)/TCTA(10nm)/CBP:R-4B(2%):GIR1(14%,X nm)/mCP:Firpic(8%,Y nm/BCP(10nm)/Alq3(40nm)/LiF(1nm)/Al(100nm)的白色全磷光有机电致发光器件(OLED),通过调节红绿发光层的厚度X与蓝光发光层的厚度Y,研究了不同发光层厚度器件发光性能的影响。研究发现:当X为23nm、Y为7nm时,器件的光效和色坐标都具有很高的稳定性,在电压分别为5、10和15 V时,色坐标分别为(0.33,0.37)、(0.33,0.37)和(0.34,0.38);在电压为5V时,电流密度为0.674mA,亮度为158.7cd,最大电流效率为26.87cd/A;利用电子阻挡材料TCTA和空穴阻挡材料BCP能够显著提高载流子的复合效率。分析认为:发光层顺序为红绿/蓝时,更有利于蓝光的出射,从而使白光的色坐标更稳定。

This paper changes the light-emitting layer and the sequence for the red and green/blue light-e- mitting layer order. The structure of white organic light-emitting diode （WOLED） is ITO/MoO3 （10 nm）/NPB（40 nm）/TCTA （10 nm）/CBP. R-4B（2%）： GIRl （14%）/mCP. Firpic（8%）/BCP（10 nm）/ Alq3 （40 nm）/LiF/Al. Adjusting the thicknesses of red,green and blue light emitting layers the device performance and luminescent mechanism are studied. Results show that when the red and green light e- mitting layer thickness is 23 nm,and the blue light-emitting layer is 7 nm,luminous efficacy and color co- ordinates stability are the best. When the voltage is 5 V, current density is 0. 674 mA, the brightness is 158. 7 cd,and the maximum current efficiency is 26.87 cd/A. When the voltage is 5 V,10 V and 15 V, the color coordinates is （0. 33,0.37） ,（0.33,0. 37） and （0.34,0. 38） ,On the one hand,When the light- emitting layer sequence order is red, and green/blue it is beneficial for stable color coordinates. On the other hand, utilizing BCP as hole blocking layer and TCTA as electron blocking layer, the composite effi- ciency of carriers can be obviously enhanced.