Efficient field emission from patterned Al-doped SnO2 nanowires

Patterned Al-doped SnO2 (Al-SnO2) nanowires have been synthesized on a common stainless steel mesh substrates by thermal evaporation of a reaction mixture of, Al and SnO powders. Field emission (FE) test demonstrate that Al-SnO2 nanowires exhibited better FE properties with higher emission current density and lower turn-on field than pure SnO2 nanowires. The turn-on field of these patterned Al-SnO2 nanowires at current density of 1 μA/cm2 is about 1.5 V/μm and the threshold field at current density of 1 mA/cm2 is 3.3 V/μm at an emitter–anode gap of 500 μm. The current density rapidly reaches 1.9 mA/cm2 at the electric field 3.7 V/μm. The current density is higher than or comparable to those of the carbon nanotubes and other one-dimensional nanostructure materials. The high current density, low threshold electric field and good stability of these patterned Al-SnO2 nanowires offer advantages as field emitter for many potential applications.