Enhanced oxidation of nanoscale In particles at the interface with a Si nanowire

We investigate the room-temperature oxidation of In nanoparticles at the tips of Si nanowires. This geometry allows a direct comparison of oxidation at the gas-indium interface and the interface to the Si nanowire. While the In2O3 at the free surface is polycrystalline with small limiting thickness, the oxidation at the nanoscale interface to Si gives rise to single crystalline In2O3 with a tenfold-enhanced thickness. Our results demonstrate interfacial modifications of oxidation at the nanoscale, which need to be considered in scaling electronic devices, and which can become a route for forming high-quality semiconductor-oxide interfaces in nanostructured materials, such as nanowires.