Sol–Gel-Derived Transparent Amino-Modified UiO-66 MOF Porous Films as Promising Photonic Platforms

The sol–gel route and dip-coating technique were combined to fabricate transparent amino-modified UiO-66 metal–organic framework (MOF) films (UiO-66-NH₂), enabling efficient in situ growth of MAPbBr₃ perovskite nanocrystals (NCs, MA = methylammonium) by strong chemical interactions between amine groups and Pb²⁺ ions. We optimized the synthesis parameters to modulate sol properties and thereby achieved a high-quality MOF film with a smooth surface (R_ms ∼ 24 nm) and exceptional transparency exceeding 90% within the visible range. By repeating dip-coating, the desired thickness of large-area MOF films (2.5 × 2.5 cm²) can be tuned within the wide range of 38 nm to 2.2 μm. Finally, we achieved confined growth of MAPbBr₃ NCs within the UiO-66-NH₂ films and investigated the growth mechanism, demonstrating the potential of UiO-66-NH₂ for functional applications. These findings suggest that the resulting UiO-66-NH₂ films hold great promise for applications in photonic devices such as light-emitting diodes, lasers, and optical sensors.