ReS2/MoSe2 Van der Waals Heterostructure Photodetectors for Polarization Imaging and Polarization‐Encoded Optical Communication

Abstract Two dimensional (2D) materials with anisotropic optoelectronic properties provide a feasible solution for polarization photodetectors, however, it is challenging to achieve simultaneous high responsivity, fast photoresponse, and good anisotropic ratio of the photocurrent ( I ph‐max / I ph‐min ). In this work, a polarization‐sensitive photodetector based on ReS 2 /MoSe 2 van der Waals heterostructures is constructed for type‐II energy band alignment with a clean contact interface. Under 532 nm laser irradiation, the photodetector has both high responsivity (89.4 A W −1 ), high‐speed response (≈30.5 µs/≈36.2 µs), and high anisotropy ratio of 3.23. The performance of the device has been enhanced for multifunctional applications, including single‐pixel polarization imaging and encrypted optical communication by combining Morse code with polarization encoding, demonstrating its potential in polarization‐related optical information applications.