Fig. 1

a Plan view SEM of as-grown InGaN/GaN nanowires grown on quartz. b High-magnification view of bright field TEM from the p-GaN region, showing the crystallinity of the nanowire. Inset shows the selective area electron diffraction pattern taken from the nanowire. c HAADF image of a single nanowire and d corresponding EDX map for Ga, e Ti, and f composite elemental mapping. Scale bar corresponds to 25 nm. g High-magnification view of the interface between the nanowire base, interlayer, and substrate. Red arrow indicates the direction for the elemental mapping. h Corresponding EDX and EELS results showing the change in elemental composition across the material interfaces. The EDX results are smoothed to remove noise