Polarization Engineering of Photodetectors Based on 2D Semiconductor Heterostructures

Polarization-sensitive photodetection, capable of simultaneously capturing the essential optical parameters of light intensity, wavelength, and polarization state, has demonstrated remarkable potential in fields such as remote sensing, biomedical diagnostics, and neuromorphic perception. Two-dimensional (2D) semiconductor heterostructures, owing to their well-defined interfaces and tunable electronic properties, can precisely control the separation and transport behavior of photogenerated carriers during the photoelectric conversion. This capability significantly enhances the performance of polarization-sensitive photodetectors. Nevertheless, achieving higher polarization ratios remains a critical challenge for the majority of 2D heterostructure-based devices. This review provides a systematic overview of recent progress in 2D semiconductor heterostructure polarization photodetectors. The review begins by outlining the working mechanisms of 2D heterostructure photodetectors constructed from representative 2D semiconductors, followed by an overview of their key performance metrics, including responsivity, detectivity, and polarization ratio. Special attention is given to strategies for improving polarization sensitivity, such as crystallographic orientation design, application of external electric fields, and integration of ferroelectric polarization fields. In parallel, the review explores emerging applications in imaging and recognition, digital signal processing, and optical communication. To conclude, this review outlines the key technical challenges, including scalable material synthesis, array fabrication, and system-level integration, and discusses future opportunities in interface engineering for controllable stacking, array-level optimization, multifunctional integration, and application-oriented device design.