A study on Si and P doped h-BN sheets: DFT calculations

Structural properties and energetics of silicon and phosphorus doped hexagonal boron nitride sheets were investigated by performing density functional theory calculations. The dopant atoms were substituted in a neutral charge state at either the B or the N site in the system as an impurity. All the systems under consideration were fully optimized. A systematic study was performed to see the effect of cell size on the calculated quantities, such as bond length, charge transfer, and defect formation energies. It was found that both silicon and phosphorus atom substitutions cause the bond lengths to increase with respect to the pristine sheets. Si atom replaced on the N site yields relatively large charge transfer from Si to the lattice. Substitutions of Si at the B site and of P at the N site are exothermic processes, while for the other cases the processes are endothermic.