Atomic scale modeling of edge a-type dislocations in InN



The atomic geometry and electronic structure of a-edge threading dislocations (TDs) in InN are investigated by combined interatomic potential and ab initio calculations. Initially isolated dislocation cores are included in supercells of ∼30 000 atoms and relaxed by Tersoff potentials and the III-species environment approach. The relaxed core structures are then extracted in the form of cluster-hybrids and total energy as well as electronic structure calculations are performed under both the generalized gradient approximation (GGA) and the local density approximation implementing modified pseudopotentials (MPP-LDA). Interatomic potentials identify the 5/7-atom core as the most energetically stable while ab initio calculations under both implemented approaches point to the 8-atom ring as most energetically stable. In the present contribution, results of density functional theory (DFT) calculations on a novel dislocation core model comprising a 10-atom ring are presented and compared to those of commonly considered cores. It is found that all considered dislocation cores modify the band structure of InN in a distinct manner due to their distinct structural features. Especially the 4- and 5/7-atom cores are identified as sources of higher electron concentrations in InN, enhancing its n-type conductivity.