Study on the Degradation of Sealed Organic Light-emitting Diodes under Constant Current
Degradation characteristics of sealed OLED devices under four different constant currents were investigated by using OLEDs aging tester. We found that the higher the applied current density was, the faster luminance decayed. There was a relationship between luminance and lifetime when the current density was within 200mA/cm2. In addition, spectrum characterization indicated that the peak wavelength didnt shift during the aging process, which implied that the carriers recombination occurred near the NPB/Alq3 interface all along even when OLEDs luminance dropped down to half of the initial value, indicating that the degradation wouldnt lead to the deviation of the carriers recombination region. Through the metallurgical microscopy observation, the number of bubbles and dark spots were noticed to increase continuously and the non-emissive area kept growing around the bubbles. It showed that bubbles would badly accelerate the formation of dark spots. By investigating luminance degradation under constant current, we draw a conclusion that OLEDs luminance degradation is not entirely coulombic. After introducing an acceleration coefficient, the formular could be applicable until the current went beyond some degree.
Xiao-Ming Xu Wen-Qing Zhu Qiang Wang Zhi-Lin Zhang Xue-Yin Jiang
School of Material Science and Engineering, Shanghai University, Shanghai 20072, China Key Laborator School of Material Science and Engineering, Shanghai University, Shanghai 20072, China Key Laborator
国际会议
北京
英文
778-781
2009-08-10（万方平台首次上网日期，不代表论文的发表时间）