Proximity-Induced Colossal Conductivity Modulation in Phosphorene

Phosphorene is a promising single-elemental two-dimensional layered semiconductor with huge potential for future nanoelectronics and spintronics applications. In this work, we investigate the effect of an organic molecule (benzene) in the close proximity of a phosphorene nanoribbon. Our extensive calculations reveal that the semiconducting nature of phosphorene remains unaffected as a result of the molecular adsorption while the transport properties go through drastic changes. Under the influence of dopant atoms and external strain, colossal changes in the conductivity are observed, with a maximum enhancement > 1500%. This effect is pretty robust against (i) variation of the system size, (ii) the type, location, and concentration of dopants and (iii) the nature and magnitude of the external strain. Furthermore, we demonstrated how a gate voltage can be used to fine tune the enhanced conductivity response in a field-effect transistor (FET) structure. Our results provide direction for phosphorene-based nanoelectronics in applications such as sensing, switching where a higher level of conduction can offer better resolution, a higher on: off ratio, and superior energy efficiency.