Multicolor and Polarization-Sensitive Photodetection of α-In2Se3/2H-MoTe2 vdW Heterostructure for Imaging and Optical Communication

Abstract

Polarization-sensitive photodetection across multiple wavelengths holds great potential for advanced optoelectronic applications. Traditional polarization photodetectors require complex polarizers and lens system, while emerging van der Waals (vdW) heterojunction photodetectors still face performance limitations. Here, we present a vdW-stacked α-In₂Se₃/2H-MoTe₂ heterostructure, enabling multicolor and polarization-sensitive photodetection across the visible and near-infrared (NIR) spectral ranges. A peak responsivity of 3.7 A·W^–1, specific detectivity of 5.1 × 10⁹ Jones, external quantum efficiency of 486%, and response time of ∼6 ms are demonstrated at the NIR wavelength of 940 nm, facilitated by the efficient photocarriers separation within the built-in electric field in the heterostructure region, as confirmed by high-spatial-resolution photocurrent mappings. The polarization sensitivity of the heterostructure, with polarization ratios of 1.40 at 638 nm and 1.07 at 1550 nm is also verified, enabling polarization imaging with a high resolution. Furthermore, the heterostructure photodetector can also act as an optical signal receiver, enabling high-fidelity and encoded optical communication. Leveraging intrinsic material properties and external field-tunability in vdW heterostructures provides a promising pathway for next-generation high-performance and multifunctional photodetectors.