Solution processed organic light-emitting diodes using the plasma cross-linking technology

[Display omitted] •Mixed acetylene and Ar plasma treatment makes the organic film surface cross-linked.•The plasma treatment for 30s does not affect the performance of OLEDs.•Cross-linking surface can resist rinsing and corrosion of organic solvent.•The surface morphology is nearly unchanged after plasma treatment.•The plasma cross-linking method can realize solution processed multilayer OLEDs. Solution processed multilayer organic light-emitting diodes (OLEDs) present challenges, especially regarding dissolution of the first layer during deposition of a second layer. In this work, we first demonstrated a plasma cross-linking technology to produce a solution processed OLED. The surfaces of organic films can be cross-linked after mixed acetylene and Ar plasma treatment for several tens of seconds and resist corrosion of organic solvent. The film thickness and surface morphology of emissive layers (EMLs) with plasma treatment and subsequently spin-rinsed with chlorobenzene are nearly unchanged. The solution processed triple-layer OLED is successfully fabricated and the current efficiency increases 50% than that of the double-layer OLED. Fluorescent characteristics of EMLs are also observed to investigate factors influencing the efficiency of the triple-layer OLED. Plasma cross-linking technology may open up a new pathway towards fabrication of all-solution processed multilayer OLEDs and other soft electronic devices.