Nanobowtie arrays with tunable materials and geometries fabricated by holographic lithography.

We introduce a highly efficient method for the fabrication of large area nanobowtie arrays (NBAs) based on a home-built tunable holographic lithography (THL) technique. By elaborately designing pattern templates, NBAs with different materials and geometric parameters can be easily obtained by a two-step approach. Both the plasmonic and semiconductor NBAs with tunable gap sizes and a high uniformity over an area of one square centimetre can be conveniently fabricated. Surface-enhanced Raman spectroscopy (SERS) performance and photoelectric properties have been demonstrated on the gold and TiO NBAs, respectively. This THL technique shows unique advantages in fabricating well-defined and large-area nanostructures in a high throughput way, facilitating practical applications in a broad range of fields of optoelectronics.