Aligned Ultralong ZnO Nanobelts and Their Enhanced Field Emission

Abstract

Aligned ultralong ZnO nanobelts with an average length of 3.3 mm and widths up to 6 μm (see figure) are synthesized on a metal substrate through a one-step process. The nanobelts obtained from this molten-salt-assisted thermal evaporation route show an emission current density of 1 mA cm–2 at an electric field of 2.9 V μm–1, resulting from their high field-enhancement factor (1.4 × 104).