Title :
A Study of Accelerated Life Test of White OLED Based on Maximum Likelihood Estimation Using Lognormal Distribution
Author :
Zhang, Jianping ; Liu, Fang ; Liu, Yu ; Wu, Helen ; Wu, Wenli ; Zhou, Aixi
Author_Institution :
Shanghai Univ. of Electr. Power, Shanghai, China
Abstract :
In this paper, accelerated life tests of white organic light-emitting diodes (WOLEDs) are conducted to obtain failure data at normal operation conditions. The lognormal distribution function was applied to describe WOLED life distribution. Log mean and log standard deviation were determined by maximum likelihood estimation. The Kolmogorov-Smirnov test was performed, and the results further confirmed that WOLED life met the lognormal distribution. Numerical results indicated that WOLED life followed the lognormal distribution. It was also found that the acceleration model was consistent with inverse power law.
Keywords :
failure analysis; life testing; log normal distribution; maximum likelihood estimation; organic light emitting diodes; Kolmogorov-Smirnov test; WOLED life distribution; accelerated life test; failure data; inverse power law; log mean deviation; log standard deviation; lognormal distribution function; maximum likelihood estimation; white OLED; white organic light emitting diodes; Acceleration; Life estimation; Maximum likelihood estimation; Organic light emitting diodes; Standards; Stress; Accelerated life test (ALT); lognormal distribution; maximum likelihood estimation (MLE); white organic light-emitting diode (OLED) (WOLED);
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2012.2215864
