Morphological Control of Ion-Induced Carbon Nanofibers and Their Field Emission Properties

摘要

Carbon nanofibers (CNFs) were fabricated on graphite plates using "Ar~+ ion sputtering method" in large amount at room temperature. The morphology of CNFs was controlled by a simultaneous carbon supply during ion sputtering. CNF-tipped cones were formed on graphite plate surfaces without carbon supply whereas those with a simultaneous carbon supply featured mainly needle-like protrusions of large size. The field electron emission (FE) properties, measured using parallel plate configurations in 10~(-4) Pa range, showed the threshold fields of 4.4 and 5.2V/μm with a current density of 1 μA/cm~2 for CNF-tipped cones and needle-like protrusion, respectively. Reliability test results indicated that CNF-tipped cones were more stable than needle-like protrusion. The morphological change after reliability test showed a so-called "self-regenerative" process and structure damage for CNF-tipped cones and needle-like protrusions, respectively.