240 10 Electrical Properties
characteristic of the double-walled boron nitride nanotubes is similar to that of
multiwall carbon nanotubes (except for the broad voltage range without conductivity), which is depicted in Figure 10.5.
Ballistic electric conductivity is a size-dependent property independent of
the kind of materials, which means this mechanism is not restricted to metallic
or semiconducting materials. As typical example of a very different conductor,
Figure 10.15 displays the current–voltage characteristic of two DNA molecules
with different length. These experimental data were obtained at room temperature [9].
Figure 10.14 Current–voltage characteristic of double-wall boron nitride nanotubes
determined at room temperature [8]. Except for the threshold voltage of 21 V, this
characteristic is similar to that depicted in Figure 10.5 for multiwall carbon nanotubes.
–60
–40
–20
0
20
40
60
voltage [V]
–6
–4
–2
0
2
4
6
current
[nA]
Figure 10.15 Current–voltage characteristic
of two DNA molecules with different lengths
[9]. These data were measured at room
temperature. Obviously, at room
temperature, the specimen length, where
ballistic conductivity is observed, is very
limited. For better visibility, the estimated
scattering ranges of the steps are shaded.
0
0.2
0.4
0.6
0.8
voltage [V]
0
0.25
0.5
0.75
1
1.25
curren
t
[nA]
DNA molecule length
5 nm
10 nm