Polarization-sensitive self-powered ultraviolet detection and image encryption enabled by RbCu2I3/SiC heterostructure

Abstract

Polarization-sensitive self-powered ultraviolet photodetectors are of great significance for advanced target recognition, machine vision, and artificial intelligence, particularly in complex optical environments where multidimensional information extraction is critical. We report a self-powered photodetector exploiting a RbCu2I3/SiC heterojunction, which affords concurrent ultraviolet spectral discrimination and polarization-resolved detection without external bias. At zero bias and 310 nm excitation, the device simultaneously achieves a light-to-dark-current ratio ∼106, a responsivity of 240 mA/W, a detectivity of 9 ×1013 Jones, a microsecond-scale transient response (τrise/τfall = 315/515 μs), and an exceptional dichroic ratio of 8.9. Collectively, these specifications establish a new performance benchmark, significantly surpassing not only commercially available all-inorganic photodetectors but also the most advanced laboratory-scale counterparts reported to date. The superior photodetection of RbCu2I3/SiC originates from the synergistic interplay of RbCu2I3's intrinsic anisotropic carrier mobility and favorable type-II band alignment, which together yield an ultralow dark current (nA-level), a high rectification ratio (∼104), and efficient spatial separation and unidirectional transport of photocarriers. Leveraging these advantages, we further demonstrate a polarization-resolved image encryption–decryption system integrated with a convolutional neural network, achieving a decryption accuracy of 98.1%. This work highlights the transformative potential of RbCu2I3/SiC heterostructures for next-generation multifunctional optoelectronics and secure optical communication, opening new avenues for intelligent photonic systems.