In Situ Growth of Ligand-Free CsPbBr ₃ QDs in a Transparent Nanoporous Poly(methylsilsesquioxane) Monolith with Superior Photoluminescence Quantum Yield and Extraordinary Stability for High-Quality LED Applications

Colloidal CsPbX₃ (X = Cl, Br, I) quantum dots (PQDs) typically suffer from severe degradation under heat, moisture, and UV/blue light irradiation, primarily due to the dynamic detachment and mismatch of surface ligands. Recently, ligand-free template-assisted strategies have emerged as an effective approach to address these challenges by regulating PQD growth through spatial confinement within nanoporous matrices. However, most reported systems are restricted to powder or thin-film forms and lack a robust, transparent, and device-compatible macroscopic architecture. In this work, we for the first time report a ligand-free in situ confined growth strategy for PQDs within a transparent nanoporous poly(methylsilsesquioxane) (PMSQ) xerogel monolith. The nanopores of the hydrophobic PMSQ template provide effective spatial confinement for the PQDs, which suppresses aggregation of PQDs and reduces nonradiative trap states, thereby enabling a high photoluminescence quantum yield exceeding 92% and excellent thermal stability, moisture stability, and photostability. Furthermore, the strategy is extended to synthesize CsPbX₃ (X = Cl, Br, I) QDs@PXMs with tunable emission across the visible spectral range from 417.6 to 674.2 nm. A white light-emitting diode fabricated using CsPbBr₃ QDs@PXMs and commercial K₂SiF₆: Mn⁴⁺ phosphors achieves a luminous efficiency of 110 lm W^-1 and a wide color gamut reaching 133% of the NTSC 1931 standard. These findings demonstrate that CsPbX₃ QDs@PXMs constitute robust and high-performance PQD-based composite materials suitable for high-quality lighting and wide-color-gamut display applications.