Stress Release of Single Crystal Arrays Bridged by SAM Interface Toward Highly Mechanically Durable Flexible Perovskite NIR Photodetector

Perovskite photodetectors with superior optoelectronic properties, lightweight, and compatibility with flexible substrates have attracted much attention in wearable electronics. However, the large bandgap, inherent brittleness, poor environmental stability, and weak interfacial adhesion interaction between perovskites and substrates hinder the application of near-infrared (NIR) wearable devices. Herein, a universal strategy to enhance the performance and mechanical stability of flexible perovskite NIR photodetector arrays is demonstrated through a combination of mussel-inspired self-assembled monolayer (SAM) bridging interface and precise modulation of the nano-array size, which enables to significantly increase interfacial adhesion, crystallinity, crystallographic orientation, and reduce mechanical stresses of perovskite single-crystal arrays. Moreover, inserting paddle-wheel metal-organic cluster ligands lead to an unprecedented small bandgap of 1.04 eV, enhanced lattice rigidity, and environmental stability for 2D perovskite. The flexible perovskite NIR photodetector arrays with superior mechanical robustness and record NIR performance are revealed with a maximum response wavelength of 1050 nm, a responsivity of 1.66 A W^-1, detectivity of 6.19 × 10¹² Jones, high fidelity imaging, and extra-long environmental stability. This work pioneers a new insight into the integration of high-performance and mechanically durable perovskite flexible wearable devices.