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 (Ps ) 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 Ps 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.