Millimeter‐range Induced Flexo‐Pyrophotronic Effect in Centrosymmetric Heterojunction for Ultrafast Night‐Photomonitoring.

Unlike the structure‐specific piezoelectric effect, flexoelectricity is a universal phenomenon that can offer a wide range of energy‐efficient, cost‐effective, mechano‐opto‐electro‐coupled applications. Even though the flexoelectric effect has been extensively studied at nanoscale, a fundamental, yet unresolved, the issue is how it can be exploited at larger scales for potential applications. Herein, the long‐range (>millimeter) stimulated and regulated impact of the localized inhomogeneous strain‐induced flexoelectric potential on centrosymmetric metal/titanium oxide heterojunction with nanoscale precision (≈5.8 nm) is demonstrated. The noticed phenomenon is attributed to the long‐range interaction between flexoelectric and build‐in potentials, which is further utilized to develop mechanically regulated (enhancement > 104%), self‐powered (i.e., 0 V), ultrafast (>10 million bits per second), and broadband (λ = 365–1720 nm) pyro‐photosensors having high responsivity (≈1.18 mA W−1). As prospective applications, proof‐of‐concept ultrafast night movement monitors (>720 km h−1), high‐performing stationery, and dynamic obstacle sensors with possible impact alerts are developed. These findings lay the groundwork for the micro‐to‐millimeter‐range flexo‐opto‐electrical coupling in centrosymmetric materials, which can have a wide variety of practical applications. [ABSTRACT FROM AUTHOR]