Wurtzite materials such as AlN and GaN could exhibit prismatic stacking faults on the (1¯2▪0) plane with a stacking fault displacement vector of ½[10▪1]. These faults thread in the [00▪1] direction and may arise in growth on the (00▪1) plane from the merging of independently nucleated islands. Merging islands that have different stacking sequences in the [00▪1] direction, for example ABAB … versus ACAC …, gave rise to the faults. The formation energy of such a stacking fault in AlN was determined by using first-principles total energy calculations to be 79meV/Å2. The perturbation caused by the highly strained four-membered rings of bonds along the boundary gave rise to shallow stacking fault states 0.1eV above the valence band maximum and 0.1eV below the conduction band minimum. These results were compared to those obtained for GaN.

Shallow Electronic States Induced by Prismatic Stacking Faults in AlN and GaN. J.E.Northrup: Applied Physics Letters, 2005, 86[7], 071901 (3pp)