Possible efficient p-type doping of AlN using Be:: An ab initio study

Spin density functional theory based ab initio study is carried out to investigate the feasibility of fabricating p-type AlN using Be as an efficient dopant. It is found that substitutional Be-Al is an acceptor with an activation energy of 0.34 eV. To overcome the low solubility of direct incorporation of Be into AlN and self-compensation from Be interstitials, we propose a hydrogen-assisted growth scheme which improves the solubility and suppresses interstitials. Oxygen is also found to be an effective codopant to activate Be in AlN. Our results suggest the possibility of improving p-type conductivity of AlN by Be doping. (C) 2007 American Institute of Physics.