Giant Flexoelectric Effect in MoS2 for High‐Performance Photodetectors and Reconfigurable Logic Computing

Abstract

Conventional two‐dimensional photodetectors suffer from intrinsic inversion symmetry that hinders carrier separation and responsivity. Here we demonstrate a self‐driven flexoelectric photodetector (FPD) requiring no external force. By transferring MoS2 onto a microwell substrate, conformal sagging induces a stable strain gradient that breaks inversion symmetry. At the optimized 4 µm microwell, the effective piezoelectric coefficient is 5.5 times that of flat regions. First‑principles calculations fill the theoretical gap for the flexoelectric coefficient of MoS2. The strain‑gradient‑induced polarization modulates the metal–semiconductor Schottky barrier, enabling unidirectional photocurrent. Under 405 nm illumination, the FPD achieves an 18‑fold enhancement in responsivity. Moreover, simply by reversing the source‑drain voltage, both NAND and NOR logic functions are realized within a single device—surpassing conventional four‑device cascades. This study establishes a device‐level strategy for utilizing the flexoelectric effect to develop high‐performance, highly integrable, and low‐power optoelectronic computing systems.