Vacuum electron field emission from SnO₂ nanowhiskers synthesized by thermal evaporation

Rod-shaped and wire-shaped SnO2 nanowhiskers were synthesized by thermal evaporating of tin powders at 900°C. Three Raman peaks (474, 632, 774 cm-1) showed the typical feature of the rutile phase of as-synthesized SnO2 nanowhiskers, which was consistent with the result of x-ray diffraction. A relatively low turn-on field of 1.37 V μm -1 at a current density of 0.1 μA cm-2 was obtained. The dependence of emission current density on the electric field followed a Fowler-Nordheim relationship. Our results indicated that SnO2 nanowhiskers had an interesting FE property as a wide band gap semiconductor.