Temperature-Dependent Field Emission Properties of 3C-SiC Nanoneedles

In this work, we report the temperature-dependent field emission properties of 3C-SiC nanoneedles (SiCNNs) in the range of room temperature (RT) to 500 degrees C. SiCNNs are synthesized via catalyst-assisted pyrolysis of a poly-aluminasilazane precursor. The obtained SiC nanostructures are needlelike shaped with numerous sharp corners around the tiny tips. Field emission characteristics show that turn-on field (E-to) of as-synthesized SiCNNs are ranged in 1.30 to 0.66 V/mu m with the temperature raised from RT to 500 degrees C. At a fixed electric field of 1.37 V/mu m, about a three-order-of-magnitude increase of the emission current level has been observed. We attribute the significant reduction of E-to and the remarkable increase of emission current to the decrease of work function induced by the raise of temperatures.