Optoelectronic Coincidence Detection with Two‐Dimensional Bi2O2Se Ferroelectric Field‐Effect Transistors

Abstract Information processing with optoelectronic devices provides an alternative way to efficiently process hybrid optical and electronic signals. Ferroelectric field‐effect transistors (FeFETs) can effectively respond to external optical and electrical stimuli by modulating their polarization states. Here, a 2D FeFET is demonstrated by the epitaxial growth of high‐quality 2D bismuth layered oxyselenide (Bi 2 O 2 Se) films on PMN‐PT(001) ferroelectric single‐crystal substrates. Upon switching the polarization direction of PMN‐PT, the authors realize in situ, reversible, and nonvolatile manipulation of the resistance of Bi 2 O 2 Se thin film ( ≈ 877%). The device simultaneously exhibits a polarization‐dependent photoresponse through visible light (λ = 405 nm) and infrared light (IR, λ = 980 nm) illumination. Combining optical stimuli with ferroelectric gating, it is demonstrated that the devices not only show nonvolatile memory and optoelectronic responses, but also show coincidence detection of visible and IR light. This work holds great potential in constructing new multiresponse and multifunction 2D‐FeFETs.