Spontaneous growth of bismuth nanowires on a sputter-deposited thin bismuth film

•100 nm diameter bismuth nanowires made by sputter-deposition•Nanowires 3–16 μm long•Diameter not strongly deposition rate dependent in range 0.03–0.09 nms− 1•Commencing deposition with temporary higher rate gave straight nanorods.

Thin films of bismuth of thickness 100 nm have been deposited onto Si(111) substrates held at 120 °C using magnetron sputter deposition. The three-inch magnetrons were operated at DC powers between 30 W and 50 W to give deposition rates between 0.03 and 0.09 nms− 1. Examination of the surface of the thin films using scanning electron microscopy revealed nanowires of diameter 80–120 nm and length between 3 and 16 μm emerging from the film. An investigation of the effect of deposition rate found little influence on the nanowire diameter, but indicated that some longer nanowires could be found on the film deposited at the lowest rate. A 20 nm film grown on glass at 110 °C shows a nanowire with dimension of around 50 nm. Using a relatively higher rate for the first 25 nm followed by a lower rate to 100 nm produced some very straight and regular nanorods.