摘要
We have successfully attained patterned carbon nanotubes grown on two-dimensional Ni arrays of square blocks of various sizes on Si by a microwave-heated chemical vapor deposition process. The Ni blocks are either freestanding or isolated by the silicon dioxide. For patterned carbon nanotube emitters, grown on freestanding Ni blocks, the emission current-density increases with the size of the Ni blocks. To the contrary, patterned carbon nanotube emitters grown on 2 μm by 2 μm Ni blocks isolated by the silicon diode have exhibited an emission behavior as excellent as the un-patterned emitters; both emitters have very low turn-on and threshold fields being at ∼0.1 V/μm and ∼1.50 V/μm, respectively and can emit current density exceeding 120 mA/cm 2 . © 2002 Elsevier Science B.V. All rights reserved.