Mechanically robust and self-healable perovskite solar cells

Skin-like self-healing electronics have been pursued for decades with limited success. The trade off between excellent electronic properties and suitable rheological properties do not allow high-performance inorganic semiconductor materials to be self-healable. Here, we report a mechanically self-healable hybrid halide perovskite semiconductor. A molecularly tailored self-healing polymer is incorporated into a polycrystalline perovskite thin film to form a composite with a bi-continuous interpenetrating network. This composite heals using synergistic grain growth and solid diffusion processes at slightly elevated temperatures. Mechanically robust and self-healable perovskite solar cells are fabricated with power conversion efficiencies over 10% and excellent stability. The healable composite is presented in flexible devices retaining 94% of their power conversion efficiency after 3,000 bending cycles and 80% performance recovery after extreme bending. These results foreshadow the use of polymer-perovskite hybrid materials for ultra-flexible and wearable energy-harvesting devices and demonstrate the effectiveness of marrying dissimilar materials to achieve unique functionalities.