Ab initio energetics of phosphorus related complex defects in synthetic diamond

We present ab initio calculation for binding energies of phosphorus (P)-related complex defects, P-hydrogen (H) and P-vacancy (V), in crystal diamond. The binding energies of P-H are found to be similar to 2.6eV and similar to 1.3eV for dissociation into neutral constituents P-H -> P-0 + H-0 and ionized ones P-H -> P+ + H-, respectively. The binding energy of P-V is very large, similar to 7.1 eV (similar to 5.4eV) for P-V -> P-0 + V-0 (P-V -> P+ + V-) The latter suggests a high possibility to cause compensation of the P-donors by themselves, self-compensation, since P-V is known as a deep acceptor. Judging from these results, P-doping of diamond should be done at H-rich conditions at a risk generating P-H, rather than at H-poor conditions. (c) 2005 Elsevier B.V. All rights reserved.