Promising Field Emission Characteristics of Polyaniline Nanotubes

Polyaniline (PANI) nanotubes have been synthesized employing chemical polymerization with acetic acid as dopant. The synthesized PANI nanotubes were characterized by Scanning electron microscope (SEM), Transmission electron microscope (TEM), Uv-visible spectroscopy and Fourier transform infrared spectroscopy (FTIR). The SEM and TEM analysis clearly reveals the formation of PANI nanotubes, with outer diameter in the range of 50-150 nm and length in several microns. The Uv-visible and FTIR spectra exhibit characteristic features corresponding to electrically conducting phase of doped PANI. Field emission (FE) studies of the PANI nanotubes were performed in planar diode configuration at a base pressure of similar to 1 x 10(-8) Torr. From the FE results, value of the turn on field required to draw an emission current density of 1 mu A/cm(2) was found to be 1.55 V/mu m and current density of 1 mA/cm(2) has been drawn at an applied field of 3.8 V/mu m. The PANI nanotubes emitter exhibited good emission current stability at pre-set value of 1 mu A over duration of more than 3 h. The ease of synthesis route and interesting field emission properties recommend the PANI nanotubes as a promising material for field emission based applications in vacuum micro-nanoelectronic devices. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3582525] All rights reserved.