Probing local electric field distribution of nanotube arrays using electrostatic force microscopy

Abstract

The local electric field distribution of nanotube arrays has been studied by using the electrostatic force microscopy (EFM) technique. The nanotube arrays were fabricated using the anodic alumina template method. Good electric contact has been proofed using contact mode conductive atomic force microscopy. The experiment shows that the EFM can provide a quantitative mapping tool to measure three-dimensional distribution of local electric field with resolution down to several nanometers. The finite difference method has been applied to calculate the electric field distribution near the surface of the nanotube array induced by a conductive tip. The results show that the field decays in a power law with exponent varies for nanotubes of different packing environments as the tip was lifted away from the top of nanotubes. The protrusion of nanotubes causes a much higher enhanced field than packing geometry. Medium packing density may enable the maximum collective emission current for such nanotube arrays of narrow diameter and height diversity.