The optimized unit cell of pristine h-BN has planer geometry with lattice constant 2.52 Å and sp 2 hybridized B-N bond of length 1.45 Å. By adding F atoms on top of Bsites and bottom of N-sites (Fig. ) in the unit cell of h-BN, the FBNF monolayer is designed which is allowed to fully relax until it achieves the favorable stable configuration. The optimized structure is buckled (0.50 Å) with lattice constant 2.66 Å and sp 3 hybridized longer B-N bond of length 1.62 Å. The details of bond lengths in optimized structures are presented in Table . The lattice constant of FBNF is 10% more than pristine structure however retains the hexagonal symmetry similar to fluorinated graphene and SiC . This increment is attributed to the larger radius of the F atom and inter-atomic repulsion. The structural stability is confirmed by calculating the cohesive energy (Equ. 1) which is -6.91 eV/atom and -4.83 eV/atom for h-BN and FBNF monolayer, respectively. The relatively smaller negative cohesive energy in FBNF is connected to the longer B-N bonding. The formation energy (Equ.