Synergistic Band Engineering in Ta 2 NiSe 5 /ReSe 2 Heterostructure for Dual‐Dimensional Imaging

ABSTRACT Next‐generation machine vision demands photodetectors capturing multidimensional optical information, such as intensity, wavelength, and polarization, within a single device. However, simultaneously achieving high sensitivity and polarization resolution remains a fundamental challenge due to conflicting material requirements. Here, we demonstrate a dual‐dimensional imaging photodetector based on a synergistically engineered Ta 2 NiSe 5 /ReSe 2 van der Waals heterostructure. The large work function difference (∼0.4 eV) between Ta 2 NiSe 5 and ReSe 2 establishes a strong built‐in electric field and forms a unilateral depletion heterojunction. This unique band alignment enables efficient photocarrier separation and unipolar transport, yielding self‐powered operation with fast response (709/85 µs). The optimized device exhibits broadband photoresponse from UV (365 nm) to near‐infrared (808 nm), achieving an outstanding detectivity (1.06 × 10 10 Jones), responsivity (287 mA/W), and low noise equivalent power (0.11 pW/Hz 1/2 ) at 405 nm. Notably, by crystallographically aligning anisotropic ReSe 2 with Ta 2 NiSe 5 , the photoexcitation and carrier extraction processes are structurally coupled, amplifying the polarization ratio to 3.34. Leveraging these capabilities, we demonstrate dual‐dimensional imaging, both broadband imaging and polarization‐resolved imaging that effectively enhances contrast in complex scattering environments. This work advances high‐performance, multifunctional optoelectronic for advanced imaging and sensing technologies.