Controlling the diameter of silicon nanowires grown using a tin catalyst

Silicon nanowires were grown on ITO-coated glass substrates via a pulsed plasma enhanced chemical vapor deposition method, using tin as a catalyst. The thin films of catalyst, with different thicknesses in the range 10–100 nm, were deposited on the substrates by a thermal evaporation method. The effect of the thickness of the thin film catalyst on the morphology of the silicon nanowires was investigated. The scanning/transmission electron microscopy images showed that the wire diameter increased as the thickness of the thin film catalyst increased. The nanowires grown using a thin film thickness of 10 nm were inhomogeneous in diameter, whereas the other thicknesses led to an increase in the homogeneity of the diameters of the nanowires. The dominant wire diameter of the grown silicon nanowires ranged from 70 to 80 nm with 10 nm catalyst thin film thickness, and increased to a range of 190–200 nm with 100 nm catalyst thin film thickness.