title: Fabrication of cone-shaped CNF/SiC-coated Si-nanocone composite structures and their excellent field emission performance.
abstract: Novel cone-shaped carbon nanofiber (CNF)/silicon carbide (SiC)-coated Si-nanocone (Si-NC) composite structures with excellent field emission (FE) performance have been fabricated by a simple microwave plasma chemical vapour deposition process. Transmission electron microscopy analyses reveal that the newly developed cone-shaped composite structures are composed of bamboo-like herringbone CNFs grown vertically on the tips of conical SiC layers with a flat-top Si cone embedded underneath. For this CNF/SiC-coated Si-NC composite array, a ultra-low threshold field of 0.32 V μm(-1) (at 10 mA cm(-2)), a large emission current density of 668 mA cm(-2) at 1.05 V μm(-1), and a field enhancement factor as high as ~48,349 are obtained. In addition, the FE lifetime test performed at a large emission current density of 200 mA cm(-2) under an applied field of 1 V μm(-1) shows no discernible decay during a period of over 260 minutes. We deduce that this superior FE performance can be attributed to the specific bamboo-like herringbone CNFs with numerous open graphitic edges and a faceted top end, and the conical base SiC/Si structures with sufficient adhesion to the substrate surface. Such a novel structure with promising emission characteristics makes it a potential material for electron field emitters.
authors.affiliation: Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan. ijteng@nctu.edu.tw
authors.forename: I-Ju
authors.initials: IJ
authors.lastname: Teng
authors.forename: Hui-Lin
authors.initials: HL
authors.lastname: Hsu
authors.forename: Sheng-Rui
authors.initials: SR
authors.lastname: Jian
authors.forename: Cheng-Tzu
authors.initials: CT
authors.lastname: Kuo
authors.forename: Jenh-Yih
authors.initials: JY
authors.lastname: Juang