Organic light-emitting diodes are prized for displays and lighting but are limited by low external quantum efficiency and by efficiency loss at high driving voltages. An international team has embedded plasmonic nanoparticle arrays in the active layers of four state-of-the-art OLED structures.

Collective surface lattice resonances of the arrays enhanced the outcoupling of light and controlled the direction and polarisation of the emission; both square arrays and flat-band lattices were demonstrated. By designing the arrays and OLED structures together, the team enhanced the electroluminescence by up to 30% at selected wavelengths and angles. QMAT's Quantum Dynamics group led by Päivi Törmä at Aalto University took part, with first author Aron Dahlberg, alongside partners in Turku, Kaunas, Eindhoven and Exeter.

The preprint has not yet been peer reviewed.

Figure: Dahlberg et al., arXiv:2607.12635 (2026), CC BY 4.0