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 Bi 2 WO 6 (BWO) is used for engineering multifunctional electronic and optoelectronic devices, including transistor, photodetector, and photosynapse devices. The well-defined BWO nanosheets ( E g ≈ 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 × 10 11 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.