Investigation on epitaxial lateral overgrowth of InGaN/GaN multi-quantum-well nanowires.

To achieve semipolar InGaN/GaN multi-quantum-well (MQW) structure, we fabricate InGaN/GaN MQW nanowires by using a combination of selectively epitaxial lateral overgrowth and patterned GaN/sapphire substrate techniques. Basing on the SEM observations, the nanowires along different crystal orientation of GaN substrate have various surface morphologies. Furthermore, cathodoluminescence measurements exhibit the dependence of the emission peaks of InGaN quantum wells on the axial direction of nanowires, being mainly attributed to the change of the morphology situation of the side facet. The shift of the peaks is larger than 30 nm as the axial direction of a nanowire varies between [1120] and [1100].