Effective Hubbard Parametrization for Optimizing Electronic Bandgap of monolayer CrI3

We perform first principles investigation to calculate the electronic bandgap of monolayer CrI3 and determine its electronic nature using SIESTA. The bandgap of CrI3 as measured by GGA-PBE exchange correlational differed from earlier experimental and theoretical findings. In this paper, we demonstrate that the bandgap value of monolayer CrI3 may be obtained by applying GGA-BLYP exchange correlational and modifying the Hubbard parameters - effective Coulomb parameter (U), effective exchange parameter (J), and Fermi cut off function (ω). CrI3 exhibits a bandgap of 1 eV in the spin-up channel and shows a direct bandgap characteristics. In case of spin-down channel, it exhibits an indirect bandgap characteristics with a band gap value of ~ 2.5 eV.