Polarization-sensitive photodetection in a two-dimensional interlayer-multiple-cation hybrid perovskite bulk single crystal

Two-dimensional (2D) hybrid Ruddlesden-Popper (R-P) and Dion-Jacobson (D-J) perovskites, which possess an intrinsic light absorption anisotropy, have taken booming status in polarization-sensitive photodetection. 2D perovskites of interlayer-multiple-cations (IMCs) represent an unprecedented type of configuration with alternating cations in the interlayer space, resulting in a distinguishing stacking model and different physical properties compared to R-P and D-J counterparts. However, the understanding of IMC perovskite bulk crystal growth and its application in polarization-sensitive photodetection remain a blank. In this work, high-quality bulk single crystals of IMC perovskite Cs 2 [C(NH 2 ) 3 ]Pb 2 Br 7 ( 1 ) were successfully grown via a facile solution process for the first time. The unique 2D bilayered IMC structure of 1 leads to an obvious optical anisotropy associated with a distinct absorption ratio of α a / α b = 1.32, which enables single-crystal detectors of 1 to exhibit fascinating polarization-sensitive photoelectric activity under incident illumination with a considerable dichroism ratio of 1.3. In addition, high-quality crystal-based devices of 1 display a notable responsivity of 6.82 mA W −1 , a particular detectivity of 2.7 × 10 9 Jones, fast response speed (∼170 μs) and benign anti-fatigue merits. This work highlights the latent opportunities of perovskites in polarization-sensitive detection and provides new perspectives for the optoelectronic device applications of them in the future. Two-dimensional perovskites of interlayer-multiple-cations (IMCs), which possess an intrinsic light absorption anisotropy, have the potential to become the candidate in polarization-sensitive photodetection.