In Situ Generation of Hydrogen Fluoride for F-Doping of Perovskite Quantum Dots

Fluorine ion doping serves as an effective strategy for enhancing the stability of perovskite quantum dots (QDs), which is crucial for constructing high-performance and highly stable optoelectronic devices. However, conventional fluorination methods often rely on highly toxic fluorine sources, such as hydrofluoric acid (HF), posing safety hazards and limiting large-scale fabrication. Herein, we propose a simple and universal in situ fluorination strategy based on the reaction between benzoyl fluoride and oleylamine under mild conditions, which safely generates HF and enables efficient fluorine doping. The incorporated fluoride ions enter the CsPbI3 lattice, effectively suppressing octahedral tilting and thereby enhancing structural stability. The resulting F-doped CsPbI3 QDs achieve a photoluminescence quantum yield close to unity and exhibit a 15-fold improvement in T95 under light illumination stability testing. Deep-red light-emitting diodes fabricated from these QDs deliver a peak external quantum efficiency of 25.7% and show a 20-fold enhancement in operational lifetime. Furthermore, this approach is successfully extended to green- and blue-emitting perovskite QD systems, demonstrating its broad potential for full-color display applications. This work provides a rational and scalable chemical pathway to address the intrinsic instability of perovskite QDs, paving the way toward efficient and durable optoelectronic devices.