Bulk Photovoltaic Effect in High-Temperature Lead-Halide Molecular Ferroelectric [C<sub>4</sub>N<sub>2</sub>H<sub>14</sub>][PbI<sub>4</sub>]
Ganghua Zhang, Zhibo Chen, Jinrong Wen, Jingshan Hou, Shu Chen, Yongzheng Fang, Yi Ren
Abstract
Hybrid organic–inorganic molecular ferroelectrics (HOIMFs) have garnered significant attention owing to their potential applications in optoelectronic and spintronic devices. However, HOIMFs with high Curie temperature ( T c ), narrow bandgap ( E g ), excellent stability, and high breakdown voltage are still very rare. Herein, we present a novel lead-halide molecular ferroelectric, (1,4-butanediammonium)PbI 4 ( 1 ), synthesized hydrothermally. 1 exhibits a ferroelectric-to-paraelectric phase transition with a high Curie temperature of 485 K, a room temperature ferroelectric hysteresis loop with a robust saturation polarization of 3.9 μC/cm 2 and strong coercivity of 33 kV/cm, and a typical semiconductor behavior with a direct bandgap of 2.28 eV. Switchable photovoltaic effect was observed in 1 -based device with a fast response time of ∼2 ms and high breakdown electric field of 80 kV/cm. Dramatically enhanced photovoltaic performance has been achieved by manipulating the ferroelectric polarization, resulting in a maximum photovoltage of V oc ∼ 0.84 V and a photocurrent of J sc ∼ 33.31 nA/cm 2 under standard AM 1.5 G illumination. This study offers a bright avenue for advancing high- T c lead-halide molecular ferroelectrics with promising potentials in photodetectors, data storage, and logical switching devices.