CPM Seminar
Toward Hybrid Silicon-Organic Molecular Devices
Bob Wolkow
Department of Physics
University of
Alberta
&
National Institute for Nanotechnology
Our understanding of and control over molecular adsorption on silicon has
advanced very significantly in the last several years. It is now possible to
provide a microscopic picture of structure and bonding in covalently attached
molecule-silicon surface systems. This detailed understanding of
adsorbate-surface structures was entirely lacking when the first wave of
enthusiasm for molecular devices crested 20 years ago. While many ideas for
molecule-scale devices have been put forward in the past, the tools - both
synthetic and analytical - to pursue those ideas did not exist. Now, the
control necessary to begin exploring ways to incorporate organic function
into existing technologies or, eventually, to make new molecule-scale devices
is within reach [1]. Experimental and modeling methods have
emerged that effectively extend the resolution of STM to see the details of
adsorbed molecule structure and bonding. In the next several years it is now
realistic to expect structures and concepts dreamed about for decades to
begin to be realized. This talk will focus on a self-directed growth process
for creating molecular nanostructures on silicon [2] and
extensions of that process [3-7].
A sampling of related activity ranging from a new process for
`easily' forming nano-tips, to a discussion of anomalously low
schottky barriers in ultra small area metal-silicon diodes will be touched
upon.
[1]
Controlled Molecular Adsorption on Si: Laying a Foundation for Molecular
Devices, R.A. Wolkow, Annual Review of Physical Chemistry, 50,
413-41, 1999.
[2]
Self-Directed Growth of Molecular Nano-Structures on Silicon, G.P Lopinski,
D.D.M. Wayner and R.A. Wolkow, Nature 406, 48 (2000).
[3]
Electronic structure and STM images of self-assembled styrene lines on a Si
(100) surface, W.A. Hofer, A.J. Fisher, G.P. Lopinski and R.A. Wolkow,
Chem Phys Lett, 365, 129-134 (2002)
[4]
`Gentle lithography' with benzene on Si(100), Peter Kruse and Robert
A. Wolkow, Appl. Phys. Lett. 81, 4422-24 (2002).
[5]
Patterning of vinyl ferrocene on H-Si(100) via self directed growth of
molecular lines and STM induced decomposition, Peter Kruse and R.A.Wolkow,
Nano Lett.; 2, 807-810 (2002).
[6]
A Self-Directed Growth Process for Creating Covalently Bonded Molecular
Assemblies on the H-Si(100)-31 Surface, Tong, X.; DiLabio, G. A.; Wolkow, R.
A.; Nano Lett.; 4, 979-983, (2004).
[7]
Ring-Opening Radical Clock Reactions for Hybrid Organic on Silicon
Nanostructures: a New Self-Directed Growth Mechanism and Kinetic Insights,
Xiao Tong, Gino A. DiLabio, Owen J. Clarkin and Robert A. Wolkow, Nano
Letters, 4, 357-360 (2004)
Thursday, September 9th 2004, 15:30
Ernest Rutherford Physics Building, room 305
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