Field emission of vertically-aligned carbon nanotube arrays grown on porous silicon substrate

Vertically aligned arrays of multi-walled carbon nanotubes were grown by pyrolysis of acetylene on iron catalytic particles within a porous silicon template via chemical vapor deposition (CVD) at 700 °C. Using this method ordered nanotubes with diameters from 75 to 100 nm could be produced. The diode configuration field emission of the CNT arrays were performed and the onset electric field is 4 V/μm and the emission current can approach 1 mA/cm² at a electric field of 9.5 V/μm. The enhancement factor of the CNT arrays (4012) is derived from the F–N plot of the experiment data. To demonstrate the uniformity of the field emission, an ITO glass substrate with phosphor coated is used as anode in the field emission experiment. The average fluctuation of the emission current density was less than 5%. The result shows that the field emission of the CNT arrays on the silicon substrate is very uniform. These carbon nanotube arrays are useful for applications in field emission displays and sensors. The fabrication method shows the feasibility of integration between carbon nanotube arrays and silicon microelectronics.