Structural characterization of InGaN multi-quantum-wells grown on high indium content InGaN template with {1 0 1¯m} faceted surface

X-ray diffraction (XRD) reciprocal space mappings (RSMs) and transmission electron microscopy (TEM) were applied to structurally characterize InGaN multi-quantum-well (MQW) alloys with a novel structure which were epi-grown successively on a rough thick n-InGaN layer with {1 0 1¯m} (2 < m < 6) faceted surface, by plasma assisted molecular beam epitaxy (MBE) on c-plane sapphire. In spite of the rugged surface of n-InGaN, the morphology of MQWs derives from the underlying InGaN layer with a special profile of V shape (named as V-MQWs). The direction of stacking for growing V-MQWs remains in [0 0 0 1] direction. The process of growth was governed in the regime of Frank-van der Merwe. Spontaneous composition modulation of InGaN, with 〈1 0 1¯m〉 modulation direction, was observed by TEM and unconventional shift of satellite peaks in reciprocal space took place in XRD (1 0 1¯ 5) RSM. The two scarce phenomena are attributed to the special morphology of V-MQWs.