High-Performance Inkjet Printed OLEDs Realized by Improved Film Morphology

Inkjet printing technology with the characteristic of patterned deposition shows great potentials in manufacturing cost-effective and large-area organic light-emitting diodes (OLEDs). However, the poor film morphology caused by “Coffee-Ring” effect in inkjet printed OLEDs (IJP OLEDs) is detrimental to develop efficient and stable device. In this work, we demonstrate that outward radial capillary flow can be retarded by increased ink viscosity, thus the “Coffee-Ring” effect has been effectively relieved. With the improved film morphology, current efficiencies (CEs) of IJP OLED were increased by 18%, more importantly, a twofold enhancement in device lifetime was also realized.