Single-phase tungsten carbide nanopillar arrays prepared by chemical vapor deposition

Single-phase tungsten carbide nanopillar arrays have been prepared by hot filament chemical vapor deposition with carbonized tungsten filaments as precursors. The structural properties and morphologies of the nanopillar arrays were characterized by XRD, SEM and HRTEM, respectively. A possible formation mechanism for the morphology was proposed. Moreover, the field emission properties of the nanopillar arrays have been studied. The Fowler–Nordheim plot of the nanopillar arrays shows an interesting linear dependence demonstrating their suitability as emitters. The nanopillar arrays show remarkable stability for several hours at a current intensity of about 5.6 × 10−7 A at 2000 V with a distance between the anode and sample of 150 μm.