where we have chosen a coordinate system such that the z-axis passes through the geometric center of NW crosssection area, the core side length, c, is depicted in Figs. and, and ∆E c = 0.50 eV is the Al 0.3 Ga 0.7 N conduction band edge discontinuity depicted in Fig. . For core-multishell NW geometries examined in this work, each separate region is described with a V CB (r) expression having the same functional form as Eqs.