Optical excitations and quasiparticle energies in the MN monolayer honeycomb structure

We calculated the electronic structure and optical properties of the AlN monolayer based on first principle many-body Green's function and Bethe-Salpeter equation formalism. We computed that the indirect (direct) band gap of the AlN monolayer honeycomb using quasiparticle correction is 5.36 eV (6.07 eV), but it has a value of 2.93 eV (3.7 eV) within the density functional theory. The calculations reveal that the optical absorption is sensitive to excitonic effects such as electron-hole interaction with binding energy of the first exciton of over 2.05 eV within the GW + Bethe-Salpeter equation calculation. The enhanced excitonic effects in the AlN monolayer can be used to. describe the optical properties in nano-optoelectronic devices. (C) 2014 Elsevier Ltd. All rights reserved.