Tunable Flexoelectric Polarization in Sb 2 Se 3 Nanowire‑Bent WSe 2 Heterojunction for Self‑Powered Polarization‑Sensitive Photodetection

ABSTRACT The flexoelectric effect serves as an effective mechanism for modulating the performance of 2D material‐based photodetectors (PDs). However, it remains challenging to generate large and controllable strain gradients while simultaneously exploiting intrinsic characteristics of strain‐inducing materials. Herein, this work constructs a WSe 2 /Sb 2 Se 3 heterojunction with a maximum bending curvature of 2.09 µm −1 , in which one‐dimensional (1D) Sb 2 Se 3 nanowires serve as both the bending template to induce conformal deformation in WSe 2 and the functional component to form an isotype heterojunction. By continuously modulating the nanowire diameter, precise control over both the induced strain gradient and the resulting flexoelectric field is achieved. Moreover, the synergistic coupling of the flexoelectric field and the intrinsic built‐in electric field optimizes the interfacial band alignment, which accelerates the extraction of photogenerated carriers, and thus delivers an exceptional zero‐bias photoresponse. Under 520 nm illumination, the device achieves an open‐circuit voltage of reaching 0.59 V alongside a zero‐bias photoresponsivity of 21.07 mA·W −1 . In addition, benefiting from the intrinsic anisotropy of Sb 2 Se 3 nanowires, the PD exhibits a dichroic ratio of 1.54 and successfully enables self‐powered polarization imaging. This work provides new insights and experimental evidence for harnessing the optoelectronic properties of 2D/1D heterojunctions and developing flexoelectricity‐tailored high‐performance self‐powered PDs.