Bulk Photovoltaic Effect in Polar 3D Perovskitoid Enables Self-Powered Polarization-Sensitive Photodetection

The family of polar hybrid perovskites, in which bulk photovoltaic effects (BPVEs) drive steady photocurrent without bias voltage, have shown promising potentials in self-powered polarization-sensitive photodetection. However, reports of BPVEs in 3D perovskites remain scare, being mainly hindered by the limited dipole moment or lack of symmetry breaking. Herein, a polar 3D perovskitoid, (BDA)Pb₂Br₆ (BDA = NH₃C₄H₈NH₃), where the spontaneous polarization (P_s)-induced BPVE drives self-powered photodetection of polarized-light is reported. Emphatically, the edge-sharing Pb₂Br₁₀ dimer building unit allows the optical anisotropy and polarity in 3D (BDA)Pb₂Br₆, which triggers distinct optical absorption dichroism ratio of ≈2.80 and BPVE dictated photocurrent of 3.5 µA cm^-2. Strikingly, these merits contribute to a polarization-sensitive photodetection with a high polarization ratio (≈4) under self-powered mode, beyond those of 2D hybrid perovskites and inorganic materials. This study highlights the potential of polar 3D perovskitoids toward intelligent optoelectronic applications.