Electrical control of polarization-resolved photodetection in GeSe/MoTe2 heterostructures for optoelectronic encryption

Abstract

Polarimetric optical encryption enables parallel information channels and enhanced eavesdropping prevention capabilities, improving data transmission capacity and information security. However, conventional systems rely heavily on bulky and discrete components such as polarizers and wave plates, which complicate device integration and miniaturization. To address these limitations, we demonstrate a polarization-resolved photodetector based on the heterostructure of GeSe/2H-MoTe2. Leveraging the type-II energy band arrangement and strong interface coupling between anisotropic GeSe and ambipolar 2H-MoTe2 layers, the device enables efficient carrier separation and broadband light response from visible to near-infrared regions. Under 638 nm irradiation, the device achieves self-powered operation with a responsivity of 1.98 A/W, a specific detectivity of 1.15 × 1011 Jones, and an external quantum efficiency of 387%. Moreover, the polarization ratio of the device is electrically tunable (1.47–3.17), enabling the realization of an XNOR-based optical encryption system in which polarization angles and gate voltages serve as optical data bits and electrical keys, respectively. This work not only presents an efficient strategy for enhancing polarization sensitivity and broadband self-powered detection but also establishes a route toward secure and reconfigurable optoelectronic information processing based on 2D van der Waals (vdW) heterostructures.