The boron-phosphorous co-doping scheme for possible n-type diamond from first principles

In this paper, we have investigated a boron-phosphorous co-doping scheme in diamond bulk for the possibility of realizing n-type conductive diamond by first-principles calculations. A comprehensive searching of B-2P complexes (a complex consisting of one boron atom and two phosphorous atoms) with different configurations have been done. Results have shown that the B-2P complexes in various forms are donor-like and can be relatively easy to form. Especially for a specific configuration (P-C-B-C-P, B-2P complex in which the P and B atoms are separated by a carbon atom), the ionization energy is as low as 109 meV. Both the formation energy and the ionization energy (3.025 eV, 109 meV) are much lower than those for the single phosphorous impurity (7.85 eV, 414 meV). It is quite encouraging to discover this complex theoretically that can be a perfect candidate for shallow donor in diamond.