Electroluminescent photoresists: Extending Moore's Law to full-color OLEDs

Abstract

The miniaturization of OLEDs is critical for next-generation ultrahigh-resolution displays and integrated photonics. However, traditional vacuum evaporation and inkjet printing methods are incompatible with the lithographic scaling processes that underpin silicon electronics, hindering true monolithic integration with CMOS circuits. Here, we present electroluminescent photoresists (ELPRs) synthesized via atom transfer radical polymerization (ATRP) that can be directly patterned by UV and electron beam lithography. These multi-arm star polymers feature a core-shell architecture designed to embed the TADF emitters within a protective host shell, segregating them from the reactive photocrosslinking moieties on the surface. We demonstrate robust processing orthogonality in sequential multilayer ELPR photolithography, enabling sub-diffraction fluorescence nanopatterns with critical dimensions down to 110 nm. We validate their device performance with full-color, UV-patterned OLEDs exhibiting external quantum efficiencies (EQEs) exceeding 13%.