Structural properties of semipolar InGaN/GaN quantum dot superlattices grown by plasma-assisted MBE

[Display omitted] ► InGaN/GaN quantum dot superlattices grown on (11-22) GaN were studied by HRTEM. ► Nominal (11-22) InGaN dots were lenticular-shaped. ► QD size and faceting increased when nucleation occurred on inclined planes. ► Strain and interaction with threading dislocations introduced indium fluctuations. ► Lattice strain analysis was correlated to the indium content. The nanoscale properties of self-assembled semipolar InGaN/GaN quantum dot (QD) superlattices, grown by plasma-assisted molecular beam epitaxy (PAMBE) on (112¯2) GaN template, were investigated by transmission electron microscopy (TEM) techniques. Preferential QD nucleation on crystal planes inclined at small angles relative to the (112¯2) plane was observed. Nominal (112¯2) 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.