Intrinsic Strong Linear Dichroism of Multilayered 2D Hybrid Perovskite Crystals toward Highly Polarized-Sensitive Photodetection

Linear dichroism of 2D materials is brought into practical operation of polarized light detection; currently, organic-inorganic 2D hybrid perovskites with the linear dichroic nature offers immense potentials within this portfolio. Here, a newly tailored 2D hybrid perovskite, (iBA)(2)(MA)Pb2I7 (1, where MA(+) is methylammonium and iBA(+) is n-isobutylammonium) is investigated, adopting a highly anisotropic bilayered perovskite motif that results in strong crystallographic-dependence of linear dichroism. Both the absorption spectra (300-650 nm) and polarized-sensitive activities of 1 exhibit the distinctive anisotropic characteristics. Consequently, based on this intrinsic linear dichroism, crystal-based photodetectors of 1 show remarkable polarized-light detecting behaviors, including quite fast response time (approximate to 300 mu s), notable photocurrent on/off ratio (>10(3)) and large dichroic ratios (I-pb/I-pc approximate to 1.20 at 520 nm, 1.23 at 637 nm). Such figure-of-merits are comparable to those of the conventional GeSe nanoflakes (the linearly dichroic ratio of approximate to 1.09 at 532 nm), revealing the great potentials of 1 for the future polarized photodetection. As an innovative work, the intrinsic anisotropy and prominent linear dichroism of 1, together with the structural flexibility, opens up a promising avenue for exploring new candidates for the 2D polarized optoelectronic applications.