Four years of air exposure: Passive surface chemical engineering to improve the stability and photoluminescence performance of CsPbBr3 perovskite quantum dot glass

Scalable and passive surface passivation strategies are essential for improving the durability and performance of perovskite quantum dot (PQD) glass materials , making them suitable for real-world optoelectronic technologies. In this study, we report a spontaneous, water-assisted surface evolution process in CsPbBr 3 PQD glass, where ambient moisture induces the gradual formation of PbBr(OH) nano-phases on the glass surface over a period of four years. This self-grown passivation layer effectively enhances the material's photoluminescence performance, boosting the photoluminescence quantum yield from 20 % to 93 % without any external treatment. Detailed structural, optical, and spectroscopic analyses confirm that the PbBr(OH) phase mitigates surface defects and suppresses non-radiative recombination. Density functional theory calculations suggest that the wide bandgap of PbBr(OH) nano-phases helps confine charge carriers within the CsPbBr 3 PQDs, further enhancing luminescence efficiency. The resulting PQD glass demonstrates remarkable stability against air, thermal, and UV exposure, making it ideal for long-term applications in solid-state lighting and other optoelectronic systems. This work offers a cost-effective, passive, and potentially scalable method for improving the performance of perovskite-based materials, with significant implications for their integration into durable and high-performance devices.