Homogeneous Freestanding Luminescent Perovskite Organogel with Superior Water Stability
- Author(s): ZHANG, YUCHENG
- Advisor(s): He, Ximin
- et al.
Metal-halide perovskites have become appealing materials for optoelectronic devices. While the fast advancing stretchable/wearable devices require stability, flexibility and scalability, current perovskite still suffers from ambient-environmental instability and incompatible mechanical properties. To break the hindrance, recently perovskite−polymer composites have shown improved in-air stability with the assistance of polymers as the embedding media. However, their stability remains unsatisfactory in high-humidity environment or when immersed in water. 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 with complex structures 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 CH3NH3PbBr3 nanoparticles (NPs) are homogeneously distributed,. The perovskite-organogels present a record-high stability, maintaining their high quantum yields for > 110 days immersing in water at different pH and temperatures. 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 LED devices 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.