New electroluminescent photoresists enable sub-100 nm OLED patterning and higher efficiency

Using atom transfer radical polymerization, a team created electroluminescent photoresists (ELPRs) featuring a core-shell star-polymer design that shields thermally activated delayed fluorescence emitters from crosslinking reactions. This structure permits direct patterning with ultraviolet or electron-beam lithography, achieving fluorescence features down to 110 nm and multicolour OLED micro-pixel arrays with external quantum efficiencies above 13 %.

The ELPRs retain high electroluminescence after crosslinking and exhibit solvent orthogonality, enabling sequential multilayer fabrication without contamination. Device measurements confirm robust performance and suggest a pathway to extend Moore’s law to organic photonics. Molecular dynamics simulations validate the spatial separation of emitters from crosslinkable groups, supporting the observed stability. The work points toward ultra-high-resolution, low-cost OLED displays and integrated on-chip photonic interconnects.