Nano Express
Strain Relief Analysis of InN Quantum Dots Grown on GaN
1 Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Universidad de Cádiz, 11510, Puerto Real, Cadiz, Spain
2 Groupe d’Etûde des Semiconducteurs, UMR 5650 CNRS, Place Eugène Bataillon, Université Montpellier II, 34095, Montpellier, France
Nanoscale Research Letters 2007, 2:442-446 doi:10.1007/s11671-007-9080-6
Published: 10 August 2007Abstract
We present a study by transmission electron microscopy (TEM) of the strain state of
individual InN quantum dots (QDs) grown on GaN substrates. Moiré fringe and high resolution
TEM analyses showed that the QDs are almost fully relaxed due to the generation of
a 60° misfit dislocation network at the InN/GaN interface. By applying the Geometric
Phase Algorithm to plan-view high-resolution micrographs, we show that this network
consists of three essentially non-interacting sets of misfit dislocations lying along
the 
directions. Close to the edge of the QD, the dislocations curve to meet the surface
and form a network of threading dislocations surrounding the system.
