Molecular-dynamics study of inversion domain boundary in w-GaN

The structures and the formation energy of inversion domain boundaries (IDBs) are investigated using the Tersoff empirical potential. Four kinds of IDBs (A and B types for IDB* and Holt) are considered. The IDBs with A type are energetically favorable compared to B type with the structural instability. The IDB* is also more stable than the Holt type in spite of fourfold and eightfold rings of bonds. We calculate the atomic configurations of the Holt IDBs induced by the interactions of the IDB* with the stacking faults I1I1 and I2I2. The stacking fault I2I2 interacted with I1I1 on the IDB induces the structural transformation from IDB* to Holt type. In the growth simulation of GaN on GaN surface with the IDB* type, the IDB* is shown in spite of its structural distortion.