Homogeneous Freestanding Luminescent Perovskite Organogel with Superior Water Stability.

Abstract

Metal-halide perovskites have become appealing materials for optoelectronic devices. While the fast advancing stretchable/wearable devices require stability, flexibility and scalability, current perovskites suffer from ambient-environmental instability and incompatible mechanical properties. Recently perovskite-polymer composites have shown improved in-air stability with the protection of polymers. However, their stability remains unsatisfactory in water or high-humidity environment. These methods also suffer from limited processability with low yield (2D film or beads) and high fabrication cost (high temperature, air/moisture-free conditions), thereby limiting their device integration and broader applications. Herein, by combining facile photo-polymerization with room-temperature in-situ perovskite reprecipitation at low energy cost, a one-step scalable method is developed to produce freestanding highly-stable luminescent organogels, within which CH₃ NH₃ PbBr₃ nanoparticles are homogeneously distributed. The perovskite-organogels present a record-high stability at different pH and temperatures, maintaining their high quantum yields for > 110 days immersing in water. This paradigm is universally applicable to broad choices of polymers, hence casting these emerging luminescent materials to a wide range of mechanical properties tunable from rigid to elastic. With intrinsically ultra-stretchable photoluminescent organogels, flexible phosphorous layers were demonstrated with > 950% elongation. Rigid perovskite gels, on the other hand, permitted the deployment of 3D-printing technology to fabricate arbitrary 2D/3D luminescent architectures.