Preparation of Patterned and Multilayer Thin Films for Organic Electronics via Oxygen-Tolerant SI-PET-RAFT

An oxygen-tolerant approach is described for preparing surface-tethered polymer films of organic semiconductors directly from electrode substrates using polymer brush photolithography. A photoinduced electron transfer-reversible addition-fragmentation chain transfer (PET-RAFT) approach was used to prepare multiblock polymer architectures with the structures of multi-layer organic light-emitting diodes (OLEDs), including electron-transport, emissive, and hole-transport layers. The preparation of thermally activated delayed fluorescence (TADF) and thermally assisted fluorescence (TAF) trilayer OLED architectures are described. By using direct photomasking as well as a digital micromirror device, we also show that the surface-initiated (SI)-PET-RAFT approach allows for enhanced control over layer thickness, and spatial resolution in polymer brush patterning at low cost.