Parametric dependence of current-voltage characteristics for scanning tunnelling microscope tip-carbon nanotube contact

Abstract

This study presents parametric dependence of current-voltage (I-V) characteristics for scanning tunnelling microscope (STM) tip-carbon nanotube (CNT) contact in rectifying mode (I 6 ¼ 0 only with V < 0), which is a special behaviour shown by the contact. In order to determine the parametric dependence for its experimentally observed I-V characteristics, a computer algorithm was developed. The I-V characteristics are dependent on temperature and tip-nanotube overlap area, which are varied within experimental range. The results revealed that the forward threshold voltage decreases with increase in temperature and tip-nanotube overlap area. The current increases sharply with increase in tip-nanotube overlap area, and is much pronounced at high temperatures. It is concluded that the I-V characteristics are more dependent on tip-nanotube overlap area than temperature. The results of the calculations are compared to experimental data obtained by Yamada [1].