Multifunctional ferroelectric heterostructure for high-performance photovoltaic, self-powered photodetection and optoelectronic synapse via non-equilibrium polarization strategy

Ferroelectrics exhibiting a unique photoelectric conversion mechanism based on spontaneous polarization have attracted significant interest for the development of new optoelectronic devices in the fields of communication, imaging, and sensors. Here, engineering non-equilibrium polarization by constructing a Bi_0.9La_0.1FeO₃/BiFe_0.95Mn_0.05O₃ (BLFO/BFMO) ferroelectric heterostructure is presented as an innovative strategy for achieving high-efficiency photoelectric responses. Specifically, a 30-fold enhancement in the short-circuit current density is achieved in BLFO/BFMO due to the effective suppression of photogenerated carrier recombination. Benefitting from the high photocurrent density, BLFO/BFMO exhibits superior photodetection performance compared with traditional perovskite ferroelectric-based photodetectors, enabling outstanding dual-mode optical communication and imaging capabilities. Moreover, the non-equilibrium polarization induces an optoelectronic synaptic behavior that is leveraged to implement a neuromorphic vision sensor based on the BLFO/BFMO heterostructure. This work opens a novel route for designing high-performance ferroelectric materials, thereby advancing the development of multifunctional optoelectronic devices.