Near fully depleted Pt/Sb2Se3/ZnO hybrid junctions for high-performance polarized detection and encrypted communication

Abstract

The field of low-dimensional polarized photodetectors has become a leading focus for optical communications, remote sensing, imaging research and other studies. Achieving high polarization anisotropy while maintaining other critical detection performance metrics continues to be a significant hurdle. In this work, self-powered hybrid junction polarized photodetectors, which are based on a Pt/Sb₂Se₃ Schottky junction combined with a Sb₂Se₃/ZnO heterojunction, are proposed. The Pt/Sb₂Se₃/ZnO hybrid junction photodetector has a high responsivity of 120 mA W⁻¹, a high specific detectivity of 10¹² Jones (1000 Hz), and an ultrafast rise/decay time (833 μs/830 μs) upon 880 nm light irradiation at zero bias. Specifically, the polarization anisotropy of the designed device is measured to be 1.69. Based on the finite element method calculation, the favorable overall photoelectric properties of the photodetectors are attributed to the consistency and synergy of the built-in electric field introduced by the near fully depleted hybrid junctions, which promote the effective separation of carriers and reduce recombination losses. Because the photodetector can be used as a polarized light receiver, it can be further applied in near-infrared encrypted communication. This work provides a promising route for the design of high-performance polarized photodetectors towards realistic applications.