Tetradentate cyclometalated platinum complex enables high-performance near-infrared electroluminescence with excellent device stability

Due to the high decay rate of the non-radiative transition of long wavelengths, the molecular design of efficient and stable near-infrared (NIR) electroluminescent materials remains a big challenge. Herein, a new tetradentate cyclometalated platinum(II) complex with an N ∧ C ∧ C ∧ N coordinated framework has been developed and used as a dopant for NIR organic light-emitting diodes (OLEDs). The complex exhibited a short-lived (0.5-1.5 µs) metal-to-ligand charge transfer (MLCT) excited state in doped and neat films. The resulting NIR OLEDs (λ EL = 730 nm) achieved maximum external quantum efficiency (EQE max ) of 5.2% and radiance of 74626 mW sr −1 m –2 . Of note, the device exhibited excellent stability with operational lifetime of 119 h for LT 90 . This work demonstrated the great potential of tetradentate platinum(II) complexes in the field of NIR OLEDs. A novel tetradentate cyclometalated platinum complex enables high-performance near-infrared electroluminescence with maximum external quantum efficiency of 5.2%, maximum radiance of 74626 mW sr−1 m−2 and LT90 of 119 h.