Structural and Electrical Irregularities Caused by Selected Dopants in Black-Phosphorus

The last few years have witnessed a great shift in research from conventional 2D materials and TMDCs (transition metals dichalcogenides) to new single element 2D materials, apart from Graphene. Among these, black-phosphorus (or phosphorene) was mostly investigated mainly due to appropriate mobility, bandgap tunability, and an achievable low off-state current or a high on/off ratio. Density functional theory (DFT) assisted calculations suggest that the geometries of metal doped double layer black-P are transformed from two dimensions to three dimensions. In order to analyze electrical behavior of pristine black-P, the I-V curves drawn based on the Landauer − Buttiker formula. Most of these curves exhibit a non-linear behavior and show a square dependency of current on applied potential. In the case of sulfur doped black-P, charge conduction can be partially hindered, possibly due to the formation of trace P4S3 that has a 'cage like' structure. The selenium doped black-P crystal shows linear characteristics, due to its semi-metallic nature, as predicted by DFT simulations. Gallium and indium doped black-P crystals exhibit ohmic character and high current density (on the order of several mA/cm2) during an application of potential, indicating the metallic nature of the material.