Field emission properties from multi-walled carbon nanotubes grown on silicon nanoporous pillar array

摘要

Multi-walled carbon nanotubes (CNTs) were grown on a silicon nanoporous pillar array (Si-NPA) by thermal chemical vapor deposition (CVD). Surface morphologies and microstructure of the resultant have been studied by a field emission scanning electron microscope (FE-SEM), Raman spectrum, transmission electron microscope (TEM) and high-resolution transmission electron microscopy (HRTEM). The composition of samples was determined by energy dispersive X-ray spectroscopy (EDS). The results showed that a great deal of CNTs, with diameter in the range of 20-70 nm, incorporated with Si-NPA and a large scale nest array of CNTs/Si-NPA (NACNT/Si-NPA) is formed. EDS analyse showed that the composition of carbon nanotubes was carbon. Field emission measurements showed that a current density of 5 mA/cm2 was obtained at an electric field of 4.26 V/μm, with a turn-on field of 1.3 V/μm. The enhancement factor calculated according to the Fowler-Nordheim theory was ～11000. This excellent field emission performance is attributed to the unique structure and morphology of NACNT/Si-NPA, especially the formation of a nest-shaped carbon nanotube array. A schematic drawing that illustrate the experimental configuration is given. These results indicate that NACNT/Si-NPA might be an ideal candidate cathode for potential applications in flat panel displays.