Abstract
The nanoscale properties of self-assembled semipolar InGaN/GaN quantum dot (QD) superlattices, grown by plasma-assisted molecular beam epitaxy (PAMBE) on (11 (2) over bar2) GaN template, were investigated by transmission electron microscopy (TEM) techniques. Preferential QD nucleation on crystal planes inclined at small angles relative to the (11 (2) over bar2) plane was observed. Nominal (11 (2) over bar2) QDs were lenticular-shaped but the QD size and faceting increased when nucleation occurred on the inclined planes. Strain and interaction with the threading dislocations introduced fluctuations in the indium concentration. Lattice strain analysis along the growth direction was correlated to the average indium content. (C) 2011 Elsevier B.V. All rights reserved.