A hybrid density functional study of silicon and phosphorus doped hexagonal boron nitride monolayer

We present a hybrid density functional study of silicon (Si) and phosphorus (P) doped hexagonal boron nitride (h-BN). The local geometry, electronic structure and thermodynamic stability of Si-B, Si-N, P-B and P-N are examined using hybrid Heyd-Scuseria-Ernzerhof (HSE) functional. The defect induced buckling and the local bond distances around the defect are sensitive to charge state modulation q = -2, -1, 0, +1 and +2. The +1 charge state is found to be the most energetically stable state and significantly reduces the buckling. Based on the charge state thermodynamic transition levels, we noted that the SiB, SiN and PB defects are too deep to be ionized, and can alter the optical properties of h-BN material.