Boosting the Stability of FAPbI <sub>3</sub> Perovskite Nanocrystal Near‐Infrared Light‐Emitting Diodes with Aromatic Ligands and Organic Host Dispersion
Haruka Abe, Mizuho Uwano, Ryota Kobayashi, Kohei Narazaki, Takuya Akiyama, Yuta Ito, Daisuke Yokota, Takao Oto, Shotaro Nishitsuji, Ryohei Yamakado, Takayuki Chiba
Abstract
Abstract FAPbI 3 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.