Supplementary Information High efficiency, full-color AlInGaN quaternary nanowire light emitting diodes with spontaneous core-shell structures on Si Renjie Wang, Xuedong Liu, Ishiang Shih, and Zetian Mi* Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada *Correspondence to: E-mail: zetian.mi@mcgill.ca; Phone: 1-514-398-7114 S1. Radial elemental profiles of representative AlInGaN nanowires The EDXS elemental profile along the radial direction of AlInGaN core-shell nanowires exhibiting 515 nm-wavelength emission and carrier lifetimes of 0.35 ns, 0.63 ns and 0.96 ns are shown in Figs. S1(a), S1(b) and S1(c), respectively. As observed in Figs. S1 and Fig. 3(c), Ga signal remains constant over the core and shell regions, and the concentration of In is high in the core and then decreases towards the lateral surfaces. Shown in Figs. S1(b) and S1(c) and Fig. 3(c), there is very little In content in the sidewall regions. By contrast, it is seen in Fig. S1(a) that In is present in the region close to sidewall. Different from the nanowires with carrier lifetime of 0.63 ns shown in Fig. S1(b), the Al signal of the nanowire of 0.96 ns shown in Fig. S1(c) was drastically reduced in the core region accompanied by two sharp bumps in the shell regions, and hence its Al-rich shells were thicker. The radial carrier confinement benefits from such radial elemental profiles shown in Fig. S1(c). This explains the increased carrier lifetime. Figure S1: (a) Elemental profiles derived from EDXS line scanning analysis along the radial direction of 515 nm emission AlInGaN nanowires with carrier lifetime of (a) 0.35 ns (shell thickness: ~3 nm), (b) 0.63 ns (shell thickness: ~9 nm), and (c) 0.96 ns (shell thickness: ~13 nm), respectively.