The open issue of the n-type conductivity and its correlation to threading dislocations in InN was addressed through first principles calculations on the electronic properties of a-edge threading dislocations. All possible dislocation core models were considered (4-, 5/7-, and 8-atom cores) and were found to modify the band structure of InN in a distinct manner. In particular, nitrogen and indium low coordinated atoms in the eight-atom core induce states near the valence band maximum and above the conduction band minimum, respectively. The formation of a nitrogen–nitrogen “wrong” bond was observed at the 5/7-atom core resulting in a state inside the band gap. The 4- and 5/7-atom cores induce occupied states resonant in the conduction band due to In–In strain induced interactions and wrong bonds, respectively. These occupied states designated threading dislocations as a source of higher electron concentrations in InN and provided direct evidence that threading dislocations contributed to its inherent n-type conductivity.

Effect of Edge Threading Dislocations on the Electronic Structure of InN. E.Kalesaki, J.Kioseoglou, L.Lymperakis, P.Komninou, T.Karakostas: Applied Physics Letters, 2011, 98[7], 072103