[kolokvij-ijs] Predavanje, ponedeljek, 21. 8. ob 13:00 - prof. dr. Peng / Kolarjeva predavalnica

[Tamara Matevc]

PREDAVANJE IJS

ponedeljek, 21. avgusta 2006, ob 13. uri

Kolarjeva predavalnica (K7),
Institut Jozef Stefan, Jamova 39, Ljubljana

prof. dr. Lian-Mao Peng
Key Laboratory for the Physics and Chemistry of Nanodevices and Department 
of Electronics, Peking University, Beijing, China

"In-situ Fabrication, Manipulation and Property Measurements of Single 
Nanotubes and Nanowires with Near Atomic Resolution"

Carbon nanotube (CNT) and nanowire materials are important building 
materials for nanotechnology. These materials may be synthesized via a 
range of physical and chemical methods, and new nanotube and nanowire 
materials are produced every day. Measurements on individual nanostructures 
remain, however, difficult and it is even more challenging to control the 
property of these nanomaterials via structure modification at near atomic 
resolution. A very promising and perhaps the best method to tackle this 
problem is to combine the scanning tunnelling microscope (STM) with 
electron microscope (EM) so that manipulation and structure modification 
may be made via a highly controllable fashion on individual nanostructure 
[1-3].

CNT can be cut, manipulated and used to form complicated patterns. This 
operation requires a correlated manipulation of the CNT by two independent 
nanomanipulators [1], and in principle complicated CNT circuit may be 
constructed this way and its electric characteristics may be measured at 
each step of the pattern construction. While it is very convenient to carry 
out manipulation and measurement on nanostructure in a scanning electron 
microscope (SEM) either on or above a substrate, the resolution of the SEM 
is limited and the vacuum level is typically not as good as in a 
transmission electron microscope (TEM). The higher resolution and vacuum 
level in a TEM has been utilized for revealing the importance of the CNT 
tip structure on its electron field emission characteristics [4] and 
effects of deformation on the conductance of the CNT [5]. In particular 
experiments of this type show clearly that the conductance of the large 
diameter multi-walled CNT is not easily affected by deformation etc. and 
these CNTs may in principle be used in the fabrication of novel 
nanoelectronic circuit as interconnects [5].

A quantitative analysis of the electric transport property of the 
semiconducting nanowire also requires the detailed structure of the contact 
and nanowire. Two terminal I-V characteritics may be measured inside TEM as 
shown in Fig. 3, and the diameter, length etc. of the nanowire may readily 
be obtained from TEM imaging and varied during experiments providing 
valuable input for the quantitative analysis of the transport property of 
the nanowires[6].

References
[1] L.-M. Peng et al., MICRON 35 (2004) 495
[2] Q. Chen and L.-M. Peng, Appl. Phys. Lett. 84(24) (2004) 4920
[3] Q. Chen, S. Wang and L.-M. Peng, Nanotechnology 17 (2006) 1097
[4] M.S. Wang et al, J. Phys. Chem. B109(1) (2005) 110; B110 (2006) 5423, 9397
[5] M.S. Wang et al., Adv. Funct. Mater. 15, (2005) 1825; 16 (2006) 1462
[6] Z.Y. Zhang et al., Appl. Phys. Lett. 88 (2006) 073102

Predavanje bo v anglescini.



Tamara Matevc
tajnica Odseka za kompleksne snovi
Institut Jozef Stefan
Jamova 39
SI - 1000 Ljubljana
tel.: +386 1 477 3220
fax: +386 1 477 3998
e-mail: tamara.matevc at ijs.si
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