Strong Coupling Hybrid Modes for Narrow-band, Directional and Polarized OLEDs.

Linearly polarized organic light-emitting diodes (LP-OLEDs) featuring high color purity and directional emission have become essential light sources for near-eye displays, holographic projection, and high-precision optical sensing. However, a strategy capable of simultaneously controlling multiple parameters including color purity, directionality, polarization, and optoelectronic efficiency has remained an unmet challenge in OLED development. Herein, we demonstrate a blue-emitting OLED that combines high color purity with highly directional transverse-electric (TE)-polarized emission, realized through a strongly photon-photon mode-coupled microcavity architecture. By hybridizing the second-order Fabry-Perot mode with the first-order grating microcavity mode, the system achieves strong coupling with a mode splitting energy of 321 me. Consequently, the resulting polarized OLED exhibits outstanding performance including a transverse-electric/transverse-magnetic polarization extinction ratio of 17.3 dB, an external quantum efficiency of 3.4%, and a narrow full width at half maximum of 17.0 nm with an angular distribution of 10°. These findings validate the practical viability of microcavity coupling for advancing optoelectronic devices, particularly in display technologies and photonic integration.