Two-Dimensional Perovskite Bi ₂ WO ₆ for Multifunctional Electronic and Optoelectronic Devices

Two-dimensional (2D) oxide perovskites show great potential as candidates for next-generation electronic and optoelectronic devices. For the first time, 2D ferroelectric perovskite Bi2WO6 (BWO) is used for engineering multifunctional electronic and optoelectronic devices, including transistor, photodetector, and photosynapse devices. The well-defined BWO nanosheets (Eg ≈ 2.75 eV) are synthesized by the chemical vapor deposition method and exhibit distinct out-of-plane and in-plane ferroelectric polarization. The individual BWO nanosheet device shows significant n-type transistor characteristics with a clockwise hysteresis. Meanwhile, the individual BWO nanosheet device can emulate light-induced synaptic functions such as “learning-forgetting-relearning” behavior. Furthermore, the individual BWO nanosheet photodetector exhibits outstanding photodetection performance at 3 V at 350 nm, including high responsivity (27.2 A W–1) and high detectivity (6.9 × 1011 Jones). This work not only provides a new candidate for 2D electronic and optoelectronic devices for various applications but also lays down the foundation for the future development of integrated sensing, storage, and neuromorphic computing devices.