Transport and field emission properties of buckypapers obtained from aligned carbon nanotubes

We produce 120-µm-thick buckypapers from aligned carbon nanotubes. Transport characteristics evidence ohmic behavior in a wide temperature range nonlinearity appearing in the current–voltage curves only close to 4.2 K. The temperature dependence of the conductance shows that transport is mostly due to thermal fluctuation-induced tunneling, although to explain the whole temperature range from 4.2 to 430 K a further linear contribution is necessary. The field emission properties are measured by means of a nano-controlled metallic tip acting as collector electrode to access local information about buckypaper properties from areas as small as 1 µm2. Emitted current up to 10−5 A and turn-on field of about 140 V/µm are recorded. Long operation, stability and robustness of emitters have been probed by field emission intensity monitoring for more than 12 h at pressure of 10−6 mbar. Finally, no tuning of the emitted current was observed for in-plane applied currents in the buckypaper.