A novel lift-off method for fabricating patterned and vertically-aligned W18O49nanowire arrays with good field emission performance

Abstract

A novel lift-off method has been developed for fabricating patterned W₁₈O₄₉ nanowires in vertical arrays and on a large scale. These W₁₈O₄₉ nanowire arrays have an average diameter of about 30 nm, and their lengths range from 2–3 μm. In every pattern of a 2 inch sample, the nanowires exhibit the same morphology and growth density. They are single crystals with monoclinic structure and grow along the [010] direction. Field emission (FE) measurements show that they have a turn-on field of 6.2 V μm⁻¹ and their emission current density can reach 500 μA cm⁻² at an electric field of 10.9 V μm⁻¹. Because the W₁₈O₄₉ nanowire patterns synthesized by this simple method still have good FE performance, comparable to many cathode nanostructures with excellent FE properties, it suggests that it may provide an effective and simple preparation technique for patterned growth of nanowire arrays in future FE applications.