LIMITATIONS TO N-TYPE DOPING IN DIAMOND - THE PHOSPHORUS-VACANCY COMPLEX

In spite of large concentrations of phosphorus being incorporated into . diamond, the material often remains insulating. It is argued that th is occurs through the formation of phosphorus-vacancy complexes which are deep accepters and compensate any donor. The complex is analyzed u sing a first-principles cluster method. In the ionized state, the defe ct is diamagnetic and cannot give rise to any internal optical transit ions although broad band donor-acceptor transitions are expected-and o bserved-in material codoped with nitrogen. (C) 1996 American Institute of Physics.