Photoconductive CdSe Nanowire Arrays, Serpentines, and Loops Formed by Electrodeposition on Self-Organized Carbon Nanotubes

Semiconducting nanowires frequently have enhanced proper- ties and unique functionality compared to their bulk counterparts. Controlling the geometry of nanowires is crucial for their integration into nanoscale devices because the shape of a device component can dictate its functionality, such as in the case of a mechanical spring or an antenna. We demonstrate a novel synthetic method for making polycrystalline CdSe nanowires with controlled geometries by using self-organized single-walled carbon nanotubes as a template for the selective electrodeposition of nanowires. Nanowires of up to hundreds of micrometers in length are formed as high-density straight arrays, as well as in the shape of serpentines and loops. These nanowires exhibit significant photoluminescence and photoconductiv- ity applicable to photodetectors and respond to illumination up to 2 orders of magnitude faster than single crystalline CdSe.