Electro-optical properties of monolayer and bilayer boron-doped C3 N: Tunable electronic structure via strain engineering and electric field

In this work, the structural, electronic and optical properties of monolayer and bilayer of boron doped C3N are investigated by means of density functional theory-based first-principles calculations. Our results show that with increasing the B dopant concentration from 3.1% to 12.5% in the hexagonal pattern, an indirect-to-direct band gap (0.8 eV) transition occurs. Furthermore, we study the effect of electric field and strain on the B doped C3N bilayer (B–C3N@2L). It is shown that by increasing E-field strength from 0.1 to 0.6V/Å, the band gap displays almost a linear decreasing trend, while for the > 0.6V/Å, we find dual narrow band gap with of 50 meV (in parallel E-field) and 0.4 eV (in antiparallel E-field). Our results reveal that in-plane and out-of-plane strains can modulate the band gap and band edge positions of the B–C3N@2L. Overall, we predict that B–C3N@2L is a new platform for the study of novel physical properties in layered two-dimensional materials (2DM) which may provide new opportunities to realize high-speed low-dissipation devices.