Highly luminescent and stable perovskite quantum dots films for light-emitting devices and information encryption

The inherent flexibility and excellent mechanical strength of lead halide perovskite quantum dots (LHP-QDs) films have attracted much attention in the fields of flexible lighting, displays, non-planar x-ray imaging, and wearable optoelectronics. Unfortunately, the complicated synthesis process and poor stability limit its practical applications, hence there is an urgent need to develop a feasible fabrication process for films to attain high device performance. Herein, a molecular level hybridization of bridged polysilsesquioxane (BPSQ) is designed as matrix to harvest both flexibility of organics and stability of inorganics, resulting in improved interfacial compatibility between the CsPbBr${}_3$ QDs and the matrix through chemical bond anchoring. The CsPbBr${}_3$@3-aminopropyl-triethoxysilane (APTES)@BPSQ films showcase bright narrow-band photoluminescence, with a photoluminescence quantum yield of 61% and a half-peak full width at half maximum of <17 nm. Notably, these films demonstrate excellent environmental stability, UV resistance, water stability (experiencing only an 18% decrease in luminescence intensity after 168 h of water immersion), and high-temperature stability (withstanding temperatures up to 500 K). Furthermore, white light-emitting diodes (WLEDs) and anti-counterfeiting patterns have been fabricated using CsPbBr${}_3$@APTES@BPSQ, highlighting their wide application potential in flexible light-emitting devices and information encryption. (© 2024 Wiley‐VCH GmbH)