Shallow donors in diamond: Be and Mg

The electronic properties of the impurities Be. Mg and the hydrogen complexes Be-H, Mg-H in diamond have been investigated by first-principle calculations. It is found that the interstitial Be- or Mg- doped diamond are of n-type metal conductivity character. Even at low impurity concentration the doped diamond also appears n-type behavior. The further results indicate that the interstitial Be or Mg doping diamond should be synthesized at H-poor conditions to obtain the n-type material because most of hydrogen atom may result in interstitial Be- and Mg- doped diamond p-type semiconductor or insulator. The substitutional Be and Mg show acceptor behaviors and may compensate other interstitial donors in diamond. our results are very helpful to the research of n-type doping in diamond for the future experimental work. (C) 2008 Elsevier B.V. All rights reserved.