An effective and efficient approach to p-type AlN by Be2:O codoping from first-principles calculations

Various Be:O-codoped AlN crystals have been investigated via first-principles calculations to evaluate the role of the different combinations in effectively and efficiently inducing p-type carriers. It is found that the O atom is favored to bond with two Be atoms. The formed Be2:O complexes decrease the acceptor ionization energy to 0.11 eV, which is 0.16 eV lower than that of an isolated Be in AlN, implying that the hole concentration could probably be increased by 2–3 orders of magnitude. The electronic structure of Be2:O-codoped AlN shows that the lower ionization energy can be attributed to the interaction between Be and O. The Be–O complexes, despite failing to induce p-type carriers for the mutual compensation of Be and O, introduce new occupied states on the valence-band maximum (VBM) and hence the energy needed for the transition of electrons to the acceptor level is reduced. Thus, the Be2:O codoping method is expected to be an effective and efficient approach to realizing p-type AlN.

Low-Resistivity p-Type Doping in Wurtzite ZnS Using Codoping Method

By using first principles calculations, we propose a codoping method of using acceptors and donors simultaneously to realize low-resistivity and high carrier concentration p-type ZnS with wurtzite structure. The ionization energy of singleNScan be lowered by introducing theIIIZn-NS(III = Al, Ga, In) passivation system. Codoping method in ZnS (2N, III) has lower formation energy comparing with single doping of N since III elements act as reactive codopants.