Water‐Resistant Tin Halide Perovskite Quantum Dots in Transparent Glass Matrix

Tin (Sn)‐based halide perovskites are regarded as environmentally friendly alternatives to toxic Pb‐based counterparts, but their practical use is severely limited by the facile oxidation of Sn 2+ to Sn 4+ , which leads to lattice distortion, phase instability, and structural degradation. Herein, we demonstrate a glass‐stabilization strategy for Sn‐based perovskite quantum dots (QDs) by overcoming the oxidation issue of Sn 2+ through a nanoporous‐template‐assisted spatial‐chemical confinement strategy. Vacuum chemical vapor deposition enables the in situ formation of CsSnBr 3 QDs within the nanoscale pores of a silicate glass template, while subsequent densification seals the pores and provides physical isolation from the external environment, yielding dense and environmentally stable lead‐free perovskite QD glass. Moreover, the CsSnBr 3 QD glass exhibits excellent long‐term environmental stability, retaining about 70% and 75% of its initial photoluminescence intensity after 120 days in water and air, respectively. This work provides a robust and facile route to overcome the intrinsic instability of Sn‐based halide perovskites, opening a new pathway toward durable lead‐free optoelectronic materials.about