Improving the bending resistance of double-layer printed flexible OLEDs with PEDOT: PSS-PEO composite HIL films

Abstract

Flexible organic light-emitting diodes (OLEDs) are expected to have excellent device performance and mechanical robustness in many areas, such as wearable electronics and display devices. For the traditional materials of OLED anode, ITO is undoubtedly the most mature transparent conductive electrode available. However, the brittle and rigid nature of ITO severely limit the development of flexible OLED. In this work, a solution blending film consisting of poly (3,4 ethylenedioxythiophene): poly (styrene sulfonate) (PEDOT: PSS) and poly (ethylene oxide) (PEO) was used as a hybrid hole injection layer, where PEO polymer in the composite films can greatly improve the bending resistance of device. The printed flexible OLEDs doped with PEO exhibit impressive mechanical durability, maintaining 80.4% of its maximum external quantum efficiency after 1000 bends at a radius of curvature of 10 mm, compared to 46.3% for the counterpart without PEO doping.

Highly Conductive Inkjet-Printed PEDOT:PSS Film under Cyclic Stretching

“…In recent decades, the demand of stretchable electronic devices such as OPV, − OLED, − and various wearable sensors − for continuous vital sign monitoring and healthcare is growing with the constant upgrading of technology. An electrode is one of the crucial components in photoelectronic devices, and indium tin oxide (ITO) plays a vital role in the transparent anode material for traditional rigid devices due to its excellent conductive properties. ,, Nevertheless, its relative brittleness and high cost in the preparation process − cannot meet the future trend of electronic devices to flexibility, low cost, and large area development; therefore, searching for stretchable transparent conductors − to replace ITO has become a research highlight in recent years. Several methods have been developed to achieve stretchable electrodes.…”