Field emission studies of Te nanorods grown on Si (111) substrate

Tellurium nanorods were grown on silicon (111) substrates by thermal evaporation. The synthesized Te nanorods were characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM), prior to the field emission investigations. The TEM image revealed that the nanorods are needle-like having diameter less than 20 nm and length in the range of 200-400 nm. The selected area electron diffraction (SAED) pattern and high resolution TEM micrographs clearly reveal the crystalline nature of the Te nanorods. The field emission studies were carried out in a planar diode (close proximity) configuration at background pressure of similar to 1 x 10(-9) mbar. An emission current density of similar to 8.5 mu A/cm(2) has been drawn at an applied field of similar to 3.2 V/mu m. The Folwer-Nodhiem plot, showed a non-linear behaviour. The high value of field enhancement factor (beta similar to 1 X 10(4)), estimated from the slope of the F-N plot, suggests that the emission is indeed from the nanometric tips of the Te nanorods. The emission current stability studied at the preset value similar to 3.5 mu A over duration of more than 3 h is found to be very good, suggesting the use of Te nanorods as promising electron source for field emission based micro/nano-electronic devices. (C) 2009 Elsevier Ltd. All rights reserved.