Supporting Data for "3D Printed Flexible Organic Light-Emitting Diode Displays"

The ability to fully 3D print active electronic and optoelectronic devices will enable novel device form factors via strategies untethered from conventional microfabrication facilities. Currently, the performance of 3D printed optoelectronics can suffer from nonuniformities in the solution-deposited active layers and unstable polymer-metal junctions. Here we demonstrate a multimodal printing methodology that results in fully 3D printed flexible organic light-emitting diode displays. The electrodes, interconnects, insulation, and encapsulation are all extrusion printed, while the active layers are spray printed. Spray printing leads to improved layer uniformity via suppression of directional mass transport in the printed droplets. By exploiting the viscoelastic oxide surface of the printed cathode droplets, a mechanical reconfiguration process is achieved to increase the contact area of the polymer-metal junctions. The uniform cathode array is intimately interfaced with the top interconnects. This hybrid approach creates a fully 3D printed flexible 8×8 display with all pixels turning on successfully.