Sub-micron pinhole detection in the cathode of organic light-emitting diodes
article
A technique is presented on tracing the sub-micron pinholes that result in black spots in organic light-emitting diodes (OLED) when exposed to ambient atmosphere. The mystery about the type and nature oftiny pinholes present in the OLED cathode that allow oxygen and/or moisture ingress in minute quan-tities causing black spot formation, is clarified. The technique can accurately locate nanodefects orpinholes in the center of black spots of various sizes, even on a centimeter scale. Pinholes in theinvestigated OLEDs were shown to be caused by different particles originating from various locations inthe device stack. Defects in the Ba-Al cathode of a solution processed polymer LED (PLED) and pinholes inthe LiF-Al cathode of a thermally evaporated small molecule organic LED (smOLED) were investigatedand compared. The technique is a powerful tool for inspection and can, thereby, accelerate the processoptimization for OLED fabrication.
TNO Identifier
862351
Source
Organic Electronics, 44, pp. 263-270.
Collation
8 p.
Pages
263-270
Files
To receive the publication files, please send an e-mail request to TNO Repository.