Electron field emission from GaN nanorod films grown on Si substrates with native silicon oxides

Abstract

GaN nanorod films have been grown on Si(001) substrates with native silicon oxides by radio-frequency plasma-enhanced molecular beam epitaxy. GaN nanorod films are made up of single-crystalline nanorods with a so-called (0001) fiber-like texture. Each nanorod is elongated along $c$ axis in perpendicular to the substrate surface and has no preferential axis in film plane. Excellent electron field emission characteristics were observed for the fabricated GaN nanorod films with a field emission threshold as low as $1.25\mathrm{V}∕\mu \mathrm{m}$ at a current density of $0.1\mu \mathrm{A}∕{\mathrm{cm}}^2$ and a field emission current density as high as $2.5\mathrm{mA}∕{\mathrm{cm}}^2$ at an applied field of $2.5\mathrm{V}∕\mu \mathrm{m}$ . These excellent characteristics are attributed to the geometrical configuration of nanorods and their good crystalline quality as well as the low electron affinity of GaN.