Highly Efficient Short‐Wavelength Infrared OLEDs at 1000 nm via Phosphorescent‐Host Engineering

Short‐wavelength infrared (SWIR) organic light‐emitting diodes (OLEDs) are highly attractive for applications in night vision, bio‐imaging, and optical communication, yet achieving efficient emission beyond 900 nm remains challenging due to severe non‐radiative losses and limited exciton utilization. Here, we introduce a phosphorescent‐host‐based exciton management strategy, in which phosphorescent materials function as hosts rather than conventional sensitizers. By simultaneously harvesting singlet and triplet excitons, this approach enables highly efficient SWIR OLEDs with an emission peak at 1000 nm. The resulting devices deliver a record external quantum efficiency (EQE) exceeding 0.22% and a radiance of 1805 mW sr − 1 m − 2 , representing record performance for SWIR OLEDs. Photophysical studies reveal that host‐mediated exciton management and triplet energy confinement are critical to suppressing energy‐loss pathways. This work establishes a general host‐engineering strategy for extending OLED emission into the SWIR region.