Strain-engineered direct-indirect band gap transition and its mechanism in two-dimensional phosphorene

Recently fabricated two-dimensional phosphorene crystal structures have demonstrated great potential in applications of electronics. In this paper, strain effect on the electronic band structure of phosphorene was studied using first-principles methods including density functional theory (DFT) and hybrid functionals. It was found that phosphorene can withstand a tensile stress and strain up to 10 N/m and 30%, respectively. The band gap of phosphorene experiences a direct-indirect-direct transition when axial strain is applied. A moderate \ensuremath{-}2% compression in the zigzag direction can trigger this gap transition. With sufficient expansion (+11.3%) or compression (\ensuremath{-}10.2% strains), the gap…

• AS
  Arizona State University