OLED Aging Detection through Voltage Noise Characterization under Constant Current

The degradation mechanisms of Organic Light Emitting Diodes (OLED) light sources are not yet fully understood. Several researchers have studied these mechanisms using different methods, such as I-V and impedance characteristics as well as photometric and colorimetric parameters. In this paper, emphasis is put on aging detection using simple, field applicable and non-obstructive approaches. More specifically, the voltage noise during continuous operations at the nominal current is investigated. The statistical properties of this parameter shift with aging. This shift was studied on a small sample set, yet it permitted to discriminate correctly between new and aged OLEDs. A number of estimators were evaluated, all possessing the same ability to detect aging signature.