Polarization-Driven Self-Powered Photodetection in a Single-Phase Biaxial Hybrid Perovskite Ferroelectric.

Self-powered photodetection driven by ferroelectric polarization has shown great potential in next-generation optoelectronic devices. Hybrid perovskite ferroelectrics that combine polarization and semiconducting properties have a promising position within this portfolio. Herein, we demonstrate the realization of self-powered photodetection in a new developed biaxial ferroelectric, (EA) (MA) Pb Br (1, EA is ethylammonium and MA is methylammonium), which displays high Curie temperature (375 K), superior spontaneous polarization (3.7 μC cm ), and unique semiconducting nature. Strikingly, without an external energy supply, 1 exhibits an direction-selectable photocurrent with fascinating attributes including high photocurrent density (≈4.1 μA cm ), high on/off switching ratio (over 10 ), and ultrafast response time (96/123 μs); such merits are superior to those of the most active ferroelectric oxide BiFeO . Further studies reveal that strong inversion symmetry breaking in 1 provides a desirable driving force for carrier separation, accounting for such electrically tunable self-powered photoactive behaviors. This work sheds light on exploring new multifunctional hybrid perovskites and advancing the design of intelligent photoelectric devices.