Effect of normal strain and external electric field on electronic properties of the GeC bilayer: A first-principles study

The electronic properties of the GeC bilayer with different stacking patterns are investigated using density functional theory. A different behavior shows up when applying normal strain and electric field (E-field). Under normal strain, the bandgap becomes very elastic and presents an indirect-to-direct bandgap transition. By applying the E-field, the intrinsic bandgap swiftly reduces to zero. The major modulation of the bandgap is mainly due to the migration of Ge-p orbitals in the conduction band. Our results reveal the flexible electronic properties of the GeC bilayer, which would provide a theoretical reference for the development of the GeC bilayer.