Nanoelectronics

The aim of this chapter is to acquaint the reader the physical principles of SE tunneling devices to be used in nanoelectronics. Based on this the charge transport properties of nanocluster assemblies in one, two and three dimensions will be discussed. By means of selected examples it will be demonstrated that ligand-stabilized nanoclusters of noble metals may be suitable building blocks for nanoelectronic devices. 

K. Uchida, in R. Waser (ed.) Nanoelectronics and Information Technology, Wiley-VCH, Weinheim, (2003) 425. 

As this volume attests, a wide range of chemistry occurs at interfacial boundaries. Examples range from biological and medicinal interfacial problems, such as the chemistry of anesthesia, to solar energy conversion and electrode processes in batteries, to industrial-scale separations of metal ores across interfaces, to investigations into self-assembled monolayers and Langmuir-Blodgett films for nanoelectronics and nonlinear optical materials. These problems are based not only on structure and composition of the interface but also on kinetic processes that occur at interfaces. As such, there is considerable motivation to explore chemical dynamics at interfaces. 

Investigations of the kinetics of hole transfer in DNA by means of pulse radiolysis of synthetic ODNs have provided details about the hole transfer process, especially over 1 /is, including the multi-step hole transfer process. Based on the investigation of the kinetics of hole transfer in DNA, development of the DNA nanoelectronic devices is now expected. An active application of the hole transfer process is also desirable from a therapeutical point of view, since hole transfer may play a role in improvement of quantum yield and selectivity of DNA scission during photodynamic therapy. The kinetics of the hole transfer process is now being revealed, although there is still much research to be performed in this area. The kinetics of adenine hopping is another area of interest that should be explored in the future. 

Because DNA is much more stable under reductive conditions, excess electron transfer may in the future, open the door to side reaction free chemistry at a distance, and may pave the way for DNA-based nanoelectronics devices. 

By changing the ultrasound power, changes in the mesoporosity of ZnO nanoparticles (average pore sizes from 2.5 to 14.3 nm) have been observed. In addition to the changes in mesoporosity, changes in the morphology have also been noted [13]. Recently, Jia et al. [14] have used sonochemistry and prepared hollow ZnO microspheres with diameter 500 nm assembled by nanoparticles using carbon spheres as template. Such specific structure of hollow spheres has applications in nanoelectronics, nanophotonics and nanomedicine. 

What would be the target in 10 to 20 years A recent EC report "Vision 2020 Nanoelectronics at the Centre of Change"18 identifies 7 items where nanosciences and nano-materials offer breakthrough applications two of them deal explicitly with sensors ... 

Report of European Nanoelectronics Initiative Advisory Council, Vision 2020 Nanoelectronics at the Centre of Change, June 2004, http //www.cordis.lu/ist/eniac/... 

Fig. 1 Sketches of break junction-type test beds for molecular transport. On the far left is a tunneling electron microscopy (TEM) image of the actual metallic structure in (mechanical) break junctions from the nanoelectronics group at University of Basel. The sketches in the middle (Reprinted by permission from Macmillan Publishers Ltd Nature Nanotechnology 4, 230-234 (2009), copyright 2009) and right (reproduced from Molecular Devices, A.M. Moore, D.L. Allara, and P.S. Weiss, in NNIN Nanotechnology Open Textbook (2007) with permission from the authors) show possible geometries for molecules between two gold electrodes, and (on the upper right) a molecule that has only one end attached across the junction...

The addressing of nanoelectronic assemblies metal-molecule (nanocluster)-metal with device-like functions, such as rectifiers, switches, or transistors requires a source and a drain, and one or more localized electronic levels. The roles of source and drain (both as working electrodes WEI and WE2) may be represented by the tip of an STM, combined with an appropriate substrate or, alternatively, a pair of nanoelectrodes see Fig. 3. 

Meindl, J. D. Chen, Q. Davis, J. A. 2001. Limits on silicon nanoelectronics for terascale integration. Science 293 2044-2049. 

Fig. 22. ETEM at 180°C in N2, illustrating the stability of gold nanorods, for nanoelectronics and catalysis applications. Gold atomic layers and surface atomic structures are visible. Surface of gold nanorod at room temperature showing twin defect lamellae on the atomic scale. They indicate interaction of the surfactant with the (110) surface forming twins to accommodate the shape misfit between the two.

J. Roncali, Oligothienylenevinylenes as a new class of multinanometer linear ir-conjugated systems for micro- and nanoelectronics, Acc. Chem. Res., 33 147-156, 2000. 

ISBN 0819441783 Proceedings of SPIE — The International Society for Optical Engineering, 4991 45-63 Nanoelectronics and Information Technology Advanced Electronic Materials and Novel Devices, pp.915-931... 

Silicon Nanoelectronics, edited by Shunri Oda and David Ferry... 

Chaudhary S, Kim JH, Ozkan M (2006). Controlled electron-beam-induced large-scale alignment of carbon nanotubes at metal electrodes. J. Nanoelectron. Optoelection. 1 211-214. 

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