Figure 4.

a Schematic of the nucleus formed on the molten Au–Zn droplet and ZnO nanowire growth at initial stages with tapering. b ZnO nanowires with tapered base and uniform long stems. c Plot of nanowire diameter vs. length for both tapered and needle-like ZnO nanowires. d Plot showing growth and tapering rates of needle-like ZnO nanowires.