Lead-Sealed Stretchable Underwater Perovskite-Based Optoelectronics via Self-Recovering Polymeric Nanomaterials.

To harness the full potential of halide perovskite based optoelectronics, biological safety, compatibility with flexible/stretchable platforms, and operational stability must be guaranteed. Despite substantial efforts, none has come close to providing a solution that encompasses all of these requirements. To address these issues, we devise a multifunctional encapsulation scheme utilizing hydrogen bond-based self-recovering polymeric nanomaterials as an alternative for conventional glass-based encapsulation. We show that Pb in physically damaged halide perovskite solar cells can be completely contained within the self-recovering encapsulation upon submersion in a simulated rain bath, as indicated by in vitro cytotoxicity tests. In addition, self-recovering encapsulation accommodates stable device operation upon casual bending and even stretching, which is in stark contrast to conventional glass-based encapsulation schemes. We also demonstrate the concept of assembling user-defined scalable modular optoelectronics based on halide perovskite solar cells and light emitting diodes through the use of self-recovering conductive nanocomposites. Finally, long-term operational stability of over 1000 h was achieved under harsh accelerated conditions (50 °C/50% RH and 85 °C/0% RH) with the incorporation of an ultrathin atomic layer deposited TiO2 barrier underneath the multifunctional encapsulation. In light of these merits, the encapsulation scheme based on self-recovering polymeric nanomaterials is proposed as a simple, but practical solution to a multifaceted challenge in the field of halide perovskites.