Basal-plane stacking faults in wurtzite-structured materials were studied by using density-functional pseudopotential calculations. The formation energies followed the trend that was exhibited by zincblende/wurtzite energy differences in the bulk materials. That is, the lowest energy was found for GaN and the highest was found for AlN. Type-I stacking faults had the lowest energy, followed by type-II stacking faults, and finally extrinsic stacking faults. Another type of intrinsic stacking fault was identified that did not seem to have been previously observed. Its energy was slightly lower than that of the type-II faults. There were no localized states in the band-gap. However, stacking faults could bound a quantum well-like region of zincblende material that was surrounded by the wurtzite host; thus giving rise to a luminescence line below the wurtzite band-gap.

C.Stampfl, C.G.Van de Walle: Physical Review B, 1998, 57[24], R15052-5