Product Code: ICAL07_N301

Two-Dimensional Carbon Nanostructures and Their Electrical Transport Properties (Invited Paper - 40 Minute Presentation)
Authors:
Yihong Wu, National University of Singapore; Singapore Singapore
Haomin Wang, National University of Singapore; Singapore Singapore
Catherine Choong, National University of Singapore; Singapore Singapore
Presented at ICALEO 2007

Being able to be made into zero-dimensional (0D), one-dimensional (1D), and two-dimensional (2D) nanostructures, carbon provides unique opportunities that other materials lack. Although tremendous efforts have been devoted to the study of 0D and 1D nanocarbons, the work on 2D nanocarbons has been just started. In the last few years, we have developed a technique to grow vertically aligned 2D carbon structures on various types of substrates. In this talk, we will focus on the electrical transport properties of 2D carbon nano-sheets using both normal metal and superconducting electrodes. Excess conductance fluctuations with peculiar temperature-dependence from 1.4 to 250 K were observed in curved 2D carbon nano-sheets with an electrode gap length of 300 and 450 nm, whereas the conductance fluctuation is greatly suppressed above 4.2 K when the electrode gap length increases to 800 and 1000 nm. The former is discussed in the context of the presence of both a small energy bandgap and a narrow flatband at the middle of the gap in the nano-graphite sheets, while the latter is attributed to the crossover from mesoscopic to diffusive transport regime. The implications of these results to device applications will be discussed.