Nanowire-density-dependent field emission of n-type 3C-SiC nanoarrays

The density of the nanowires is one of the key issues for their field emission (FE) properties of the nanoarrays, since it plays an important role on the electron emission sites and field screening effect. Here, we reported the nanowire-density-dependent FE properties of the n-type 3C-SiC nanoarrays. The highly oriented and large-scale SiC nanoarrays were grown on the 6H-SiC wafer via pyrolysis of polyureasilazane by adjusting the thicknesses of Au films used as the catalysts. The densities of the nanoarrays were tunable to be similar to 2.9 x 10(7), similar to 4.0 x 10(7), and similar to 5.7 x 10(7) nanowires/cm 2 by controlling the Au film thicknesses of 50, 70, and 90 nm, respectively. The measured FE characteristics disclosed that the turn-on fields of the samples could be tailored to be of similar to 1.79, 1.57, and 1.95 V/mu m with the increase of the densities, suggesting that a suitable nanowire density could favor the enhanced electron emission from the SiC nanoarrays with improved emission sites and limited field screening effects. (C) 2015 AIP Publishing LLC.