Lithographically controlled wetting

Lithographically controlled wetting (LCW) is a rather simple, fast and low-cost fabrication process suitable for large-area nanopatteming. The technique is based, like the previously described method, on stamp-assisted deposition of a soluble material from a solution (Cavallini Biscarini, 2003). A scheme of the LCW working principle is shown in Fig. 3.24. 

FIGURE 3.18 (a) Schemes of lithographically controlled wetting applied on isotropic phase (b) OM images in the bright field of the stamp and (c) with cross polars of the patterned Pc film Reprinted with permission from Reference 126. Copyright 2009 John Wiley Sons, Inc. For a color version of this figure, see the color plate section. 

M. Cavalllni and F. Biscarini, Nanostructuring conjugated materials by lithographically controlled wetting. Nano Lett, 3,1269-1271 (2003). 

The introduction of SAMs on localized areas of a substrate allows straightforward further functionalization and directed assembly of nanoparticles. By using chemistry, specific binding can be introduced, allowing the control of nanoparticle assembly onto lithographic patterns. Wet-chemical self-assembly of nanoparticles is particularly attractive for the fabrication of nanoparticle-based nanostructures because of its compatibility with various kinds of substrates with complex shapes. In this section, conventional and nonconventional patterning techniques for the chemical assembly of nanoparticles will be highlighted. 

The advantages of lithographic methods are good size controllability and structural uniformity. However, since these methods rely on 2D self-assembling array structures, the enhancements are limited only on surfaces. It is therefore impossible to observe a sample in a bulk matrix or in a solution. Though the number of studies remains limited, wet chemical synthesis of Al and indium nanocrystals has been reported [22-26]. Al nanocrystals 50-100 nm in size have been successfully fabricated using alane derivatives as precursors and molecules with one or a pair of... 

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