Particle lithography

Velegol used a so-called particle lithography technique in which colloids were deposited on a flat solid surface, after which heterocoagulation of macromolecules and or particles could take place on the exposed areas [132-135]. Anisotropic assemblies of colloids can be manufactured via this route. 

Snyder CE, Yake AM, Feick JD, Velegol D (2005) Nanoscale functionalization and site-specific assembly of colloids by particle lithography. Langmuir 21(11) 4813-4815... 

In the traditional lithography approach, researchers continued to consider the idea that modem STM (scanning tunnel Microscopy) could be the proper tool for the formation of two-junction systems when working with very small particles. This consideration had related the studies of single-electron phenomena to the concept of quantum dots (Glazman and Shechter 1989). 

As an alternative approach towards the above requirement, Somorjai introduced the method of electron lithography [119] which represents an advanced HIGHTECH sample preparation technique. The method ensures uniform particle size and spacing e.g. Pt particles of 25 nm size could be placed with 50 nm separation. This array showed a uniform activity similar to those measured on single crystal in ethylene hydrogenation. The only difficulty with the method is that the particle size is so far not small enough. Comprehensive reviews have been lined up for the effect of dispersion and its role in heterogeneous catalysis [23,124,125]. 

On detailed electrical characteristics of a SET transistor utilizing charging effects on metal nanoclusters were reported by Sato et al. [26]. A self-assembled chain of colloidal gold nanoparticles was connected to metal electrodes, which were formed by electron-beam lithography. The cross-linking of the particles as well as their connection to the electrodes results from a linkage by bifunctional organic molecules, which present the tunnel barriers. 

A similar route has been followed most recently by Weiss et al. who have fabricated a multi-island SE device from self-assembled ID gold nanocrystal chains [28]. They assembled thiol-stabilized 50 nm Au particles in a chainlike structure and used subsequently electron-beam lithography for electrode fabrication. Here it has to be... 

In order to investigate this effect, ordered arrays of metallic nano-islands were fabricated on glass substrates by a process of natural lithography using monodisperse polystyrene nanospheres. The metal particle dimensions were tailored in order to tune the plasmon resonance wavelength to match the spectral absorption of the fluorophore. The fluorophore, Cy5 dye, which is widely used in optical immunoassays and has a medium quantum efficiency ( 0.3), was used in this preliminary study of the plasmonic enhancement effect. 

In lithography, particles can damage the printed pattern either by imbedding themselves in the resist or by casting shadows from the mask... 

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