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.