Enhanced field emission characteristics in metal-coated Si-nanocones.

Metallic gold (Au) and platinum (Pt) thin films were deposited on silicon nanocones (Si-NCs) by sputtering to elucidate the effects of work function and conductivities on the field electron emission characteristics of surface-modified Si-NCs. The results showed that for Pt/Si-NCs and Au/Si-NCs, although the turn-on field defined at a corresponding current density of 10 μA cm(-2) only improved from 4.20 V μm(-1) for bare Si-NCs to 3.65 and 2.90 V μm(-1), respectively, the emission current density measured at 5.00 V μm(-1) was enhanced by orders of magnitude, reaching 1.82 mA cm(-2) for Au/Si-NCs. Compared to those obtained from various surface-modified Si-nanostructures, such as ZnO/Si-nanopillars and ferroelectrics/Si-nanotips, the current results represent an interesting alternative route for producing surface-modified Si-NCs that might be useful for optical and electronic applications.