Revealing photovoltaic behavior in 2D hybrid perovskite ferroelectric single-crystalline microwire arrays for self-powered photodetectors

Hybrid perovskite ferroelectrics produce a revival of interest in ferroelectric photovoltaics because of the robust ferroelectricity coexisting with superior semiconducting properties. An electric field via perovskite ferroelectrics can affect their photovoltaic behavior; however, the fundamental understanding of the electric-field-induced effects remains comparatively elusive. Herein, (EA)2(MA)2Pb3Br10 single-crystalline microwire arrays (MWs) are synthesized for the fabrication of self-powered photodetectors and characterized with evident in-plane multiaxial ferroelectricity by piezoresponse force microscopy (PFM) measurements. Upon systematic investigations via a dynamic poling process, including electrical-poling-dependent photocurrent, Kelvin probe force microscopy (KPFM) mapping and ferroelectric polarization switching, we reveal that the coupling of ion migration and ferroelectric photovoltaic effect dominate the photovoltaic behavior within (EA)2(MA)2Pb3Br10 MWs. Such electric-field-induced effects are responsible for the self-powered ability in (EA)2(MA)2Pb3Br10 MWs-based photodetectors with accelerated response time, switchable photoelectric responses and large short-circuit current density. Our findings provide fundamental insight into the photovoltaic behavior under an electric field in perovskite ferroelectrics, and the electrical-poling-manipulated dynamics pave the way for innovative self-powered optoelectronic devices.