First-Principles Insights into the Tuning Mechanisms of Electronic Transport in Violet Phosphorene via Defect and Dopant Engineering

Violet phosphorene (VP), a promising allotrope of phosphorus, exhibits distinctive semiconducting properties for next-generation nanoelectronic and optoelectronic applications. However, the systematic understanding and comparative assessment of how defects and doping govern the electronic transport properties of VP remains limited, due to the difficulty of experiment control. Here, we employ first-principles calculation based on density functional theory (DFT) combined with the nonequilibrium Green’s function (NEGF) formalism to systematically investigate the transport properties of VP under varying oxygen concentrations, structural defects, and doping. The calculations reveal that oxygen adsorption concentration governs the transition from enhanced p-type conductivity to ambipolar switching. Vacancies defects drastically boost current density by introducing defect states or shifting the Fermi level, while oxygen substitution modulates conduction depending in a site-dependent manner. Elemental doping exhibits group-dependent modulation, with groups IIIA-VA preserving p-type behavior, whereas group VIA inducing a transition to n-type. These results underscore the utility of atomistic transport simulations in uncovering defect- and dopant-induced mechanisms and highlight defect/dopant engineering as a viable strategy for modulating the electronic properties of VP-based devices.