Field emission from in situ-grown vertically aligned SnO2 nanowire arrays

Abstract

Vertically aligned SnO2 nanowire arrays have been in situ fabricated on a silicon substrate via thermal evaporation method in the presence of a Pt catalyst. The field emission properties of the SnO2 nanowire arrays have been investigated. Low turn-on fields of 1.6 to 2.8 V/μm were obtained at anode-cathode separations of 100 to 200 μm. The current density fluctuation was lower than 5% during a 120-min stability test measured at a fixed applied electric field of 5 V/μm. The favorable field-emission performance indicates that the fabricated SnO2 nanowire arrays are promising candidates as field emitters.

Figure 1

Morphology characterization of the prepared SnO₂ nanowire arrays. A (a) typical SEM image and (b) HRTEM image.

Figure 2

X-ray diffraction pattern (a) and Raman spectrum (b) of the prepared SnO₂ nanowire arrays.

Figure 3

Field-emission current density as a function of the applied electric field. The measurements were performed at various anode-cathode separations of 100, 150, and 200 μm.

Figure 4

Fowler-Nordheim plots of the field emission current densities of the in situ-grown SnO₂ nanowire arrays.

Figure 5

Time dependence of the emission current of the in situ-grown SnO₂ nanowire arrays. The characterization was measured at a fixed applied voltage (500 V) with an anode-cathode separation of 100 μm.