Boosting the Stability of FAPbI₃ Perovskite Nanocrystal Near-Infrared Light-Emitting Diodes with Aromatic Ligands and...

FAPbI₃ perovskite nanocrystals (NCs) are promising for near-infrared (NIR) light-emitting diodes (LEDs) but face challenges in crystal stability and operational device lifetime. Here, it demonstrated that combining 2,2-diphenylethylamine (DPEA) aromatic ligand exchange with dispersion in π-conjugated small-molecule host materials significantly enhances photostability and operational device stability. The DPEA ligand exchange (4.4%) improved compatibility with host materials, and photoluminescence quantum yields of 87.5% (vs 78.4% for neat NC film) by suppressing energy transfer between NCs. Host-dispersed NC films exhibited uniform domain structures and enhanced photostability under continuous excitation. When applied to NIR-LEDs, host-dispersed NC film achieved electroluminescence at 742 nm, a higher spectral radiance of 39.9 W sr^-1 m^-2, and an external quantum efficiency of 11.1%. The operational lifetime extended tenfold to 5.2 h, compared to 0.4 h for neat NC-LEDs. These findings highlight the potential of organic host matrices to overcome critical stability challenges in perovskite optoelectronics.