Bulk Single Crystal Growth of a Two-Dimensional Halide Perovskite Ferroelectric for Highly Polarized-Sensitive Photodetection※

Low-dimensional semiconductors, especially recent emerging two-dimensional halide perovskites, have shown great potential in extensive optoelectronic applications due to their large structural anisotropy, unique quantum well effect and excellent semiconductor properties. Meanwhile, the bulk photovoltaic effect with a highly sensitive angle-resolved photoresponse arising from ferroelectric materials presents a promising approach for highly polarized-sensitive photodetection. Despite the blooming development of two-dimensional halide perovskite ferroelectric materials, it is a great challenge to grow bulk single crystals of two-dimensional halide perovskite ferroelectric, which restricts their further applications in polarized-sensitive optoelectronic devices. This work mainly focuses on the developing of low-dimensional halide perovskite ferroelectric crystals with excellent photoelectric response. Two-dimensional (2D) halide perovskite ferroelectric (iPA)(2)EA(2)Pb(3)I(10) (iPA=isopentammonium, EA=ethylammonium) was synthesized by a solution method through the reaction of stoichiometric lead acetate, isoamine and ethylamine in concentrated aqueous hydroiodic acid. Meanwhile, high quality centimeter-size single crystals of ferroelectric (iPA)(2)EA(2)Pb(3)I(10) with the max dimensions up to 15 mmx15 mmx3 mm have been grown via temperature cooling method. On the basis of grown bulk single crystals, further investigations on the crystal structure, optical properties measurements and electrical properties characterization were carried out. The photoelectric response performance and polarization photodetection performance of photoelectric detectors based on the compound ferroelectric single crystal assembly. The result indicated that the unique two-dimensional perovskite structure endows (iPA)(2)EA(2)Pb(3)I(10) with strong optical anistropy, narrow bandgap (1.80 eV) and fascinating photoelectric features (on/off ratio=10(3)). Strikingly, the fabricated photodetectors based on ferroelectric crystal (iPA)(2)EA(2)Pb(3)I(10) manifest excellent photoelectric features, including large dichroism ratio (2.3), high responsibility (193 mA.W-1) and photodetectivity (7.0x10(11) Jones), better than most photodetector based on intrinsic optical anisotropy of 2D materials. This work will be of great significance to lay a foundation for the exploring of multifunctional halide perovskites and points out the direction for bulk grown of highly anisotropic halide perovskite ferroelectric crystals and promotes their further applications in highly polarized-sensitive photodetection.