Electro-optical properties of monolayer and bilayer boron-doped C₃N: 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 C₃ 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−Gr@2L. A transition from semiconductor to metal is emerged in the B−Gr@2L with AA stacking. 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.