Low-Symmetry and Nontoxic 2D SiP with Strong Polarization- Sensitivity and Fast Photodetection

摘要

The in-plane anisotropic feature of 2D layered materials has captured enormous research interest due to their application in polarization-sensitive photodetection. Here, silicon phosphide (SiP), as a novel member of group IV-V 2D materials, is first introduced to the anisotropic 2D materials family with a high in-plane anisotropy. The low-symmetry structure, optical and optoelectronic properties are investigated systematically. Impressively, the photodetectors based on 2D SiP demonstrate high performance with low dark current, a fast response speed of 30 mu s, and a strong anisotropic photoresponse with an anisotropic factor of 2.9. Furthermore, a strong polarization-sensitive photodetector with a dichroic ratio up to 2.3 is realized based on the intrinsic linear dichroism of 2D SiP. This work not only provides an insight into the in-plane anisotropic properties of 2D SiP, but also sheds light on its great potentials in anisotropic optoelectronic applications.