Elastically bendable chiral metal halide crystals

Metal halide single crystals exhibit superior optoelectronic properties, promising for applications in optics and energy. However, they are inherently brittle, which has posed a major challenge for use in flexible electronics. Here, we report the elastic bending in a family of chiral lead halide crystals R-(AP)PbI3 ∙ H2O, S-(AP)PbI3 ∙ H2O, R-(AP)PbI3, and S-(AP)PbI3, (AP = 3-amino-1,2-propanediol) that originates from their rigid-flex structural motif. Upon mechanical bending, the AP+ molecular units flex and rotate, causing the molecular interactions to reorganize and effectively dissipate stress. Meanwhile, the rigid [PbI3]− metal-halide chains maintain the structural integrity of the lattice, thereby conferring exceptional elastic flexibility. The devices fabricated using these crystals with a facile nonwoven manner show significantly higher sensitivity to underwater ultrasound waves than piezoelectric ceramics. Our work paves the way for integration of bendable metal halide crystals into next-generation electronic devices. Chiral metal halide crystals exhibit elastic bending via a rigid–flexible structural motif, which enables their application in underwater ultrasound sensing