Preparation and characterization of a novel flexible substrate for OLED

In this study, we developed a novel flexible organic light emitting diodes (OLEDs) substrate by simple annealing treatment on the cyclic olefin copolymer (COC). After proper thermal treatment the optical transparency of the flexible plastic substrate increased. This could evidently be observed by visible spectra. In addition, some of the infrared absorption band is enhanced after annealing, since a molecular rearrangement has occurred. The moisture resistant ability of the flexible COC substrate was investigated using the water vapor permeation measurement. Surface roughness of the plastic substrate is reduced to 1.382 nm after thermal treating which can be measured by atomic force microscopy. On the other hand, the operating voltage and the lighting efficiency of the OLEDs with flexible COC substrate are much better than the poly(ethylene terephthalate) substrate which also is also proven in this study.