Field emission characteristics of carbon nanofibers grown on the electroplated copper micro-tips
W-Y Sung, W-J Kim, S-M Lee, H-S Yoo, H-Y Lee, S-K Joo and Y-H Kim
Seoul National University, KR
carbon nano structures, low temperature growth, field emission,
Carbon nanofibers (CNFs) were synthesized on micro-copper tips by using direct current plasma enhanced chemical vapor deposition of C2H2 and NH3 gas at 480℃. The copper micro-tips were uniformly formed by high current electroplating and were coated with Ti and Cu buffer layers to prevent copper micro-tips from high temperature damage. Nickel thin film deposited on the copper micro-tips coated with Ti and Cu buffer layers used as a catalyst. Figure 1 shows that the copper micro-tips have a straight shape with the length of about 20 ㎛ and diameter of 300-500 nm. Figure 1 also shows CNFs grown on the copper micro-tips. The CNFs have many small protrusions with very small tip radius, which attribute to good field emission characteristics. Figure 2 shows that the turn-on voltage of the CNFs was about 2.7 V/㎛ with an emission current density of 10 ㎂/cm2, and the maximum emission current density of 3.3 mA/cm2 was observed from the area of 0.2827cm2, at the electric field of 6.55 V/㎛. The Fowler-Nordheim plot showed a good linear fit, indicating that the emission current of carbon nanofibers follows a typical Fowler-Nordheim behavior.
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Nanotech 2006 Conference Program Abstract