Strain‐Induced Piezo‐Optoelectronic Coupling in Monolayer MoS 2

Piezo‐optoelectronic coupling, the direct modulation of photoresponse by strain‐induced piezoelectric polarization, is a theoretically promising route to adaptive, programmable optoelectronics, yet it remains experimentally elusive in scalable two‐dimensional systems. Here, we present large‐area monolayer MoS 2 as a robust platform for probing and controlling this coupling at the atomic limit, and a single device made on it demonstrates integrated functionality for energy generation, strain sensing, and photodetection within a unified configuration. Using dual AC resonance tracking piezoresponse force microscopy, we quantify an out‐of‐plane piezoelectric coefficient ( = 0.64 pm/V) and demonstrate a pronounced, strain‐tunable internal piezoelectric polarization that enables exciton dissociation under low bias and illumination, distinct from conventional photodetection approaches. While absolute responsivity is modest, the observed strain‐induced enhancement of photocurrent and the clear correlation with measured piezoresponse reveal that mechanical deformation can be leveraged as a precise control knob for charge separation and light–matter interaction in ultrathin semiconductors. These findings provide direct experimental insight into piezo‐optoelectronic coupling, establishing monolayer MoS 2 as a multifunctional and scalable platform for future studies of coupled electromechanical photonic phenomena and for the development of programmable optoelectronics, hybrid sensors, and next‐generation flexible devices.