Dislocation core structures in (0001) InGaN
Rhode, S. L. and Horton, M. K. and Sahonta, S.-L. and Kappers, M. J. and Haigh, S. J. and Pennycook, T. J. and McAleese, C. and Humphreys, C. J. and Dusane, R. O. and Moram, M. A.
Threading dislocation core structures in c-plane GaN and InxGa1−xN (0.057 ≤ x ≤ 0.20) films were investigated by aberration-corrected scanning transmission electron microscopy. a-type dislocations are unaffected by alloying with indium and have a 5/7-atom ring core structure in both GaN and InxGa1−xN. In contrast, the dissociation lengths of (a + c)-type dislocations are reduced, and new 7/4/9-atom ring and 7/4/8/5-atom ring core structures were observed for the dissociated (a + c)-type dislocations in InxGa1−xN, which is associated with the segregation of indium near (a + c)-type and c-type dislocation cores in InxGa1−xN, consistent with predictions from atomistic Monte Carlo simulation
Department of Materials
Imperial College London
Royal School of Mines
London, SW7 2AZ - UK