In-Situ Self-Encapsulated Tin-Halide Perovskites for Air-Functional Near-Infrared Light-Emitting Diodes

Tin-halide perovskites are emerging as exceptional materials for near-infrared light-emitting diodes (NIR-LEDs). However, their extreme oxygen sensitivity remains a significant obstacle to practical applications. This work presents a facile yet effective strategy to overcome this limitation by designing self-encapsulated tin-halide perovskite films. Incorporating a rational molecule, 4,4'-diaminodiphenyl sulfone, into precursors, it forms isolated tin-iodide perovskite particles that are encapsulated in situ, achieving outstanding air stability. The resulting films show high crystallinity, reduced trap density, and mitigated p-doping density, boosting radiative charge recombination to reach an impressive photoluminescence quantum yield approaching 50%. Leveraging these advancements, the resulting NIR-LEDs demonstrate a record-breaking peak external quantum efficiency of 12.4%, accompanied by a substantial improvement in operational lifetime. Notably, for the first time, we demonstrated a functional tin-iodide perovskite-based device in ambient air. This work provides a robust pathway for realizing high-performance and stable tin-halide perovskite-based optoelectronic devices, addressing critical challenges for their widespread application.