Polarization-Sensitive Photodetectors Based on Highly In-Plane Anisotropic Violet Phosphorus with Large Dichroic Ratio.

Anisotropic 2D layered materials with distinctive anisotropic electronic band structures and optical response are promising for practical applications in polarization imaging and sensors. Nonetheless, many of the currently reported polarized photodetectors based on anisotropic 2D materials are constrained by the low polarization responsivity and low linear dichroism ratio. Here a high-performance polarization-sensitive photodetector based on the novel in-plane anisotropy 2D violet phosphorus (VP) crystal is reported. The angle-resolved polarized Raman spectroscopy (ARPRS) study and the anisotropic electrical transport measurements revealed the highly in-plane anisotropy phonon vibration and electrical properties of VP crystal. The anisotropic ratio of electron mobility is calculated to be 2.7 at room temperature. Moreover, a polarization-sensitive photodetector based on the VP nanosheet shows high photoresponsivity of up to 341 A W-1 and a linearly dichroic ratio of up to 3.9, which is much larger than most other anisotropic 2D materials. These results indicate that the anisotropic VP crystal would be suitable for polarization-sensitive photodetectors, which leads to a promising perspective for future novel electronic and optoelectronic devices. [ABSTRACT FROM AUTHOR]