Researchers have fabricated ultrafine indium-oxide–tin nanowires on substrates such as silicon, glass, stainless steel and copper foil1. The nanowires are transparent at visible and near-infrared wavelengths, making them potentially useful for developing various optoelectronic devices.
Studies have shown that cracks readily form in thin-film electrodes on bending, degrading the performance of electronic devices. However, reports demonstrate that networks of nanowires or nanotubes offer superior mechanical properties to thin-film electrodes, and thus have the potential to enhance the performance of electronic devices.
To exploit this superiority of nanowires over thin films, the researchers grew nanowires from an alloy of tin and indium oxide on substrates at low substrates temperatures in the range 150–450°C without using any catalysts or additional oxygen. They then explored the transmission properties of the nanowires at visible and near-infrared wavelengths. The optical and electrical properties of nanowire films grown on glass substrates were investigated.
At visible and near-infrared wavelengths, the nanowire films showed less reflection than a bare glass substrate. This low reflection may be attributed to light trapping in the nanowires. All the nanowire films exhibited good antireflection properties.
The indium oxide and tin alloy acted as a self-catalyst for nanowire growth. The nanowires had a uniform morphology over the whole substrate, and the films were highly transparent. This large-area growth is expected to find use in industrial applications. "These nanowire films will be useful for fabricating light-emitting diodes, dye-sensitized solar cells and flat-panel displays," says R. Rakesh Kumar, a co-author of the study.
