Electron field emission properties on ultra-nano-crystalline diamond coated silicon nanowires

Abstract

Ultra-nano-crystal line diamond (UNCD) nano-emitters were prepared by coating UNCD films on the tip of silicon nanowire (SiNW) templates by microwave plasma-enhanced chemical vapor deposition process. The electron field emission properties of the UNCD/SiNW nano-emitters varied markedly with the pre-seeding process for the SiNW-templates. The direct ultrasonication process is more efficient in the formation of the diamond nuclei than the carburization/ultrasonication process, yielding UNCD/SiNWs nano-emitters with better electron field emission properties. The electron field emission can be turned on at (E(0))(UNCD/SiNW4)= 3.75 V/mu m, yielding a large electron field emission current density of (Je)(UNCD/SiNW4)= 11.22 mA/cm(2) at an applied field of 9.75 V/mu m. These characteristics are significantly better than those of bare SiNWs or planar UNCD films. (C) 2008 Elsevier B.V. All rights reserved.