Realization of In‐Plane Polarized Light Detection Based on Bulk Photovoltaic Effect in A Polar Van Der Waals Crystal
Wentao Wu, Zhijin Xu, Yunpeng Yao, Yi Liu, Guankui Long, Lina Li, Maochun Hong, Junhua Luo
Abstract
Abstract 2D van der Waals materials are widely explored for in‐plane polarized light detection owing to their distinctive in‐plane anisotropic feature. However, most of these polarized light‐sensitive devices root in their low symmetry of in‐plane structure and work depending on external power sources, which greatly impedes the simplification of integrated devices and sustainable development. Bulk photovoltaic effect (BPVE), which separates photoexcited carriers via built‐in electric field without an external power source and shows an angle‐dependence on light polarization, is promising for self‐powered polarized light detection to break through the restriction of in‐plane anisotropy. Herein, a 2D lead‐free van der Waals perovskite (Cl‐PMA) 2 CsAgBiBr 7 ( 1 , Cl‐PMA = 4‐Chlorobenzylamine) is successfully designed through the dimension reduction strategy. 1 exhibits BPVE with an open‐circuited photovoltage up to ≈0.5 V. Driven by the BPVE, self‐powered in‐plane polarized light detection with a large polarization ratio of 1.3 is obtained for 1 . As far as it is known, the first in‐plane polarized light detection in hybrid perovskites based on BPVE is realized here. This work highlights the strategy of designing lead‐free hybrid perovskite with BPVE and opens an avenue for exploiting in‐plane highly sensitive polarized light detection in 2D van der Waals materials.