Exploring a Fatigue‐Free Layered Hybrid Perovskite Ferroelectric for Photovoltaic Non‐Volatile Memories

Abstract Through a functional unit‐transmutation strategy, a fatigue‐free layered hybrid perovskite ferroelectric (C 6 H 5 CH 2 NH 3 ) 2 CsPb 2 Br 7 ( BCPB ) has been developed, which demonstrates stable spontaneous polarization ( P s ) of 6.5 μC cm −2 and high Curie temperature up to 425 K. Meanwhile, BCPB shows splendid bulk photovoltaic effect (BPVE) properties with noticeable zero‐bias photocurrent density (5 μA cm −2 ), and high on/off switching ratio of current (over 3×10 5 ); these merits even overmatch the most known ferroelectric semiconductor BiFeO 3 . The unique structure with self‐regulated net electrical charged layers gives rise to the fatigue‐free feature of P s and BPVE (no significant fatigue after 10 8 polarity switching cycles), promoting the potential applications of BCPB in photovoltaic non‐volatile memories. This work offers an efficient approach for exploring fatigue‐free semiconducting ferroelectrics as well as excavates their further applications in next‐generation electronic devices.