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

摘要:

基于红绿/蓝双发光层,制作了结构为ITO/MoO ₃(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15V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。

Abstract:

This paper changes the light-emitting layer and the sequence for the red and green/blue light-emitting layer order.The structure of white organic light-emitting diode (WOLED) is ITO/ MoO₃(10nm)/NPB(40nm)/TCTA(10nm)/CBP:R-4B(2%) :GIR1(14%)/mCP:Firpic(8%)/BCP(10nm)/Alq₃(40nm)/LiF/Al.Adjusting the thickne sses 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 emitting layer thickness is 23nm,and the blue light-emitting layer is 7nm,luminous efficacy and color coordinates stability are the best.When the voltage is 5V,current density is 0.674mA,the brightness is 158.7cd, and the maximum current efficiency is 26.87cd/A.When the voltage is 5V,10V and 15V,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 efficiency of carriers can be obviously enhanced.