Flexible polymeric light-emitting diodes

摘要

Flexibility is one of the most frequently mentioned advantages if organic light emitting diodes are compared to other display technologies. In this contribution we show how the different functional layers respond to applied mechanical stress. To characterize the intrinsic flexibility of the stacked layers in an organic light emitting diode separately, samples with anode and cathode layers on flexible plastic substrates are investigated separately first. We observe that the ITO can withstand more than 30 000 bending cycles, concave as well as convex, down to a radius of curvature of 8 mm without apparent damage. Furthermore, the operational characteristics of completed flexible organic light-emitting devices built on indium-tin oxide coated poly(ether sulfone) under single bending cycles are investigated. Performance data taken at 15 mm radius of curvature show no influence compared to the non-planar conditions.