All‐Dielectric Mie Resonances Enabled Giant Anisotropy in High‐Symmetry 2D Material Photodetector: A New Paradigm for Polarized Optoelectronics

Abstract Compared to traditional photodetectors, polarized photodetectors can not only recognize light intensity, but also enable identification of polarization state. In recent years, a number of polarized photodetectors based on 2D materials with structural anisotropy have been achieved. However, these materials have encountered a series of shortcomings including poor stability, high cost and difficult integration. Transition metal chalcogenides (TMDs) offer potential solutions but exhibit limited anisotropy due to structural symmetry. Here, polarization‐sensitive TMD photodetectors are explored by coupling 2D channels with all‐dielectric Si nanostrips. Leveraging Mie resonance‐induced near‐field enhancement, the Re‐WSe 2 /WS 2 photodetector achieves a high detectivity of 4.66 × 10 12 Jones under a self‐powered mode, along with short rise/fall time of 133.4/376.4 µs. Most importantly, a remarkable anisotropic ratio of 6.8, which outperforms intrinsic anisotropy ratios of numerous 2D counterparts, has been realized. Finite‐difference time‐domain simulations attribute this to polarization‐sensitive Mie resonances from anisotropic spatial confinement. Taking advantages of high photosensitivity and strong anisotropy, high‐resolution imaging and dual‐channel optical communication have been realized. This work advances multifunctional photodetector design through synergistic light‐matter interactions, offering a viable pathway to circumvent material‐level symmetry limitations.