Fig. 3

a SEM image (80° tilted angle view) of InSb nanowires grown with an individual In particle source placed at the center of the furnace and an Sb particle source at an upstream position. The substrate is placed at a downstream position, 12 cm away from the source. The heating at the furnace center is set at 550 °C for 1 h and then the system is cooled down naturally to room temperature. b HRTEM image of an as-grown InSb nanowire. c EDX spectrum of the nanowire, where the ratio of In:Sb close to 1:1 can be extracted. d FTT pattern for a selected segment of the nanowire, which indicates that the nanowire is a zincblende crystal