Tuning the electronic and magnetic properties of triangular boron nitride quantum dots via carbon doping

The energetic stability, electronic and magnetic properties of carbon-doped triangular boron nitride quantum dots (BNQDs) were investigated using first principle calculation within density functional theory (DFT). Different edge structures, doping positions, and carbon concentrations are considered. We found that the substitutional C atom energetically prefers to reside in the minority sublattice of the BNQDs, and the planner structures of the BNQDs are well preserved. When the carbon dopant moves from the inner to the outer region of the BNQDs, the HOMO–LUMO gap decreases in an oscillating way, which is even smaller than that of graphene quantum dots. After carbon doping, BNQDs have non-zero magnetic moment ground states. There is an impurity state above or below the Fermi level of C-doped BNQDs, depending on substituting majority or minority sublattice. This offers a promising way of tuning the electronic and magnetic properties of BNQDs.