Structural and optoelectronic characterization of anisotropic two-dimensional materials and applications in polarization-sensitive photodetectors

The omnipresence of polarized light on the surface of the earth, a result of atmospheric scattering, underscores the significance of detecting this light and extracting valuable information regarding the phase and polarization angle. In recent years, there has been a surge in research on polarization-sensitive photodetectors that utilize anisotropic two-dimensional (2D) materials. The essence of these 2D polarization-sensitive photodetectors is rooted in the anisotropic characteristics that arise from the asymmetric crystal lattice of the 2D materials in question. This anisotropy is manifested in both optical and electrical behaviors due to the asymmetrical nature of the crystal structure. This article systematically categorizes anisotropic 2D materials and offers an insightful overview of their crystal structures. It also introduces various optical and electrical characterization techniques designed to elucidate the anisotropic properties of these materials. The focus of the article then shifts to detailing the current state of research in the realm of anisotropic 2D material-based polarization-sensitive photodetectors. It provides a comprehensive description of the working principles behind polarization-sensitive photodetectors with different structural designs, shedding light on the underlying mechanisms that enable their polarization sensitivity. In conclusion, the article summarizes the findings of this review, highlighting the advancements and challenges in the field. Additionally, this review proposes several forward-looking recommendations to guide the future trajectory of research and development in the domain of 2D material-based polarization-sensitive photodetectors.