Role of electrodeposition parameters on stoichiometry of InSb nanowires

The effect of electrolyte pH on the properties of electrodeposited indium antimonide (InSb) nanowires grown in anodic alumina oxide (AAO) template will be presented. At a pH of 1.7, the InSb nanowires were found to be rich in antimony (Sb) and had rough surfaces. Though the surface and bulk of the InSb nanowire is intrinsically n-type, when InSb is grown as a Sb-rich material it shows p-type behavior, attributed to the Sb antisite and indium (In) interstitial defects. At low-pH, the effect of citrate ions on the electrodeposition is minimal, resulting in different deposition potential of In and Sb. The low pH favors adsorption of Sb anions, resulting in a high density of intrinsic defects in the nanowire. The p-type behavior was verified by measuring the electrical properties of a single InSb nanowire connected in a field-effect-transistor type configuration. The nanowires had a hole concentration of \textasciitilde 1.9$\times$ 10$^{\mathrm{16\thinspace }}$cm$^{\mathrm{-3}}$ with a field effect hole mobility of \textasciitilde 507 cm$^{\mathrm{2}}$V$^{\mathrm{-1}}$s$^{\mathrm{-1}}$, and high on-off current ratio of the order of 10$^{\mathrm{3}}$.