Abstract
The purpose of this study is to produce a material containing nano-tip-structure carbon material and nanocrystalline diamond (NCD) film with high field emission effect. It can be applied to ultrathin monitor or micro-resolution X-Ray Tube, owing to its high power advantages and lower energy cost. Materials with excellent field emission properties usually show a low turn-on field, high emission current density, high stability, and long lifetime. However, these four characteristics are usually seen in different carbon materials, but it is very difficult to find them in the same material. Therefore, in this study, a hybrid material with the properties of high chemistry stability from nanocrystalline diamond, high aspect ratio from carbon nanotube and sharp edge from carbon nanoflake ball has been fabricated. A hybrid material consisting of carbon nanotubes (CNTs) and carbon nanoflake balls (CNFBs) was successfully synthesized on NCD film by microwave-plasma-assisted chemical vapor deposition using a H2/CH4/N2 ratio of 4:1:2 at 80 torr for 30 min and the precursor used was a sol-gel solution containing ferric nitrate, tetrabutyl titanate, and n-propanol. The carbon hybrid material (CNFB-CNT-1s-NCD-2 h) exhibited excellent field emission properties, with its turn-on field being 1.89 V/µm. It also showed two-level field enhancement factors (2151and 6997) for different electric fields. The emission current density of the hybrid remained was higher than 0.55 mA/cm2 for more than 50 h and was 0.89 mA/cm2 even after 50 h of continuous emission.