Publications
Interaction of the N vacancy with H and Mg acceptors in p-type GaN
Results from recent experimental studies suggest that the N vacancy (V{sub N}) may compensate Mg acceptors in GaN in addition to the compensation arising from H introduced during growth. To investigate this possibility further, density-functional-theory calculations were performed to determine the interactions of V{sub N} with H, Mg, and the MgH center in GaN, and modeling was performed to determine the state populations at elevated temperatures. The results indicate that V{sub N}H and MgV{sub N}H complexes with H inside the vacancy are highly stable in p-type GaN and act to compensate or passivate Mg acceptors. Furthermore, barriers for formation of these complexes were investigated and the results indicate that they can readily form at temperatures > 400 C, which is well below temperatures typically used for GaN growth. Overall, the results indicate that the V{sub N} compensation behavior suggested by experiments arises not from isolated V{sub N}, but rather from V{sub N}H and MgV{sub N}H complexes with H located inside the vacancy.