Novel phosphorus-based 2D allotropes with ultra-high mobility

Electronic structure calculations based on density functional theory were performed to investigate structural, mechanical, and electronic properties of phosphorene-based large honeycomb dumbbell (LHD) hybrid structures and a new phosphorene allotrope, referred to as ψ″-P. The LHD hybrids (i.e., X₆P₄; X being C or Si or Ge or Sn) and ψ″-P have significantly higher bandgaps than the corresponding pristine LHD structures, except the case of C₆P₄, which is metallic. ψ″-P is found to be a highly flexible p-type material which shows strain-engineered photocatalytic activity in a highly alkaline medium. The carrier mobility of the considered systems is as high as 10⁵ cm² V^-1 s^-1 (specifically the electron mobility of LHD structures). The calculated STM images display the surface morphologies of the LHD hybrids and ψ″-P. The predicted phosphorus-based 2D structures with novel electronic properties may be candidate materials for nanoscale devices.