The metallicity of B-doped diamond surface by first-principles study

The first-principles study is performed to boron-doped diamond (100) and (111) surface structures, respectively. The total energy values of the relaxed structures indicate that the more stable structure can be obtained for diamond (100) structure when the carbon atoms in the surface few layers are substituted by boron atoms; while for diamond (111) structure, the boron atoms have a more uniform distribution in it. From the calculated energy band structures we can find an obvious insulator–metal transition with the doping of boron atoms, which is in good agreement with previous experimental and theoretical studies. Our calculated results also indicate that not only the boron concentration, but also the sites of the boron atoms in diamond can affect the stability and metal–insulator transition of boron-doped diamond.