Electrophoretic deposition and field emission properties of patterned carbon nanotubes

Patterned carbon nanotubes on silicon substrates were obtained using electrophoretic method. The carbon nanotubes migrated towards the patterned silicon electrode in the electrophoresis suspension under the applied voltage. The carbon nanotubes arrays adhered well on the silicon substrates. The surface images of carbon nanotubes were observed by scanning electron microscopy. The field emission properties of the patterned carbon nanotubes were tested in a diode structure under a vacuum pressure below 5 10 4 Pa. The measured emission area was about 1.0 mm2. The emission current density up to 30 mA/cm2 at an electric field of 8 V/mm has been obtained. The deposition of patterned carbon nanotubes by electrophoresis is an alternative method to prepare field emission arrays.