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

Through a functional unit-transmutation strategy, a fatigue-free layered hybrid perovskite ferroelectric (C₆ H₅ CH₂ NH₃ )₂ CsPb₂ Br₇ (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 3×10⁵ ); these merits even overmatch the most known ferroelectric semiconductor BiFeO₃ . 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 10⁸ 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.