New two-dimensional arsenene polymorph predicted by first-principles calculation: robust direct bandgap and enhanced optical adsorption

In this work, we predict a new polymorph of 2D monolayer arsenic. This structure, named delta-As, consists of a centrosymmetric monolayer, which is thermodynamically and kinetically stable. Distinctly different from the previously predicted monolayer arsenic with an indirect bandgap, the new allotrope exhibits a direct bandgap characteristic. Moreover, while keeping the direct bandgap unchanged, the bandgap of monolayer delta-As can be adjusted from 1.83 eV to 0 eV by applying zigzag-direction tensile strain, which is pronounced an advantage for solar cell and photodetector applications.

Automated summary

In this study, a new polymorph of 2D monolayer arsenic, named delta-As, with a direct bandgap characteristic was predicted. The bandgap of monolayer delta-As can be adjusted from 1.83 eV to 0 eV by applying zigzag-direction tensile strain, making it advantageous for solar cell and photodetector applications.