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

Abstract

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 Cs₂[C(NH₂)₃]Pb₂Br₇ (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 × 10⁹ 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.