Polarization-Sensitive and Broadband Photodetection Based on a Mixed-Dimensionality TiS₃/Si p–n Junction

The capability to detect the polarization state of light is crucial in many day-life applications and scientific disciplines. Novel anisotropic 2D materials such as TiS₃ combine polarization sensitivity, given by the in-plane optical anisotropy, with excellent electrical properties. Here, the fabrication of a monolithic polarization-sensitive broadband photodetector based on a mixed-dimensionality TiS₃/Si p–n junction is demonstrated. The fabricated devices show broadband responsivity up to 1050 nm, a strong sensitivity to linearly polarized illumination with difference between the two orthogonal polarization states up to 350%, and a good detectivity and fast response time. The discussed devices can be used as building blocks to fabricate more complex polarization-sensitive systems such as polarimeters.