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Honolulu, HI, United States, 2006/08/01 - The fabrication of ultrafine structures beyond the limits of conventional lithography is a topic of tremendous importance and is expected to play a significant role in the realization of futuristic nanotechnology..
It is also equally important to develop functional material systems of ultrafine dimensions in order to achieve this goal. An important step towards realization of nanodevices is self-organized nanopatterning of functional structures. A new technique, which might be called ‘chemical lithography’, enables the regular assembly of optically active nanoparticles on a silicon surface.
An international group of researchers report the fabrication of ultrafine luminescent structures through nanoparticle self-assembly. They report their findings in the July 6, 2006 online edition of Nanotechnology.
"In order to effectively utilize the nanostructures as functional elements in nano devices, absolute controllability of their properties, such as the size, shape and spatial distribution, is essential" Kuniyil Prabhakaran, first author of the paper, explains to Nanowerk. The problems associated with the growth of materials to fabricate periodic arrays of quantum dots can be overcome by substituting nanoparticles for quantum dots.
In their approach, the researchers utilize a spatially controlled difference in reactivity for the formation of periodic arrays of nanoemitters. The silicon surface is prepared in such a way that regions with different reactivities are spatially separated and therefore can be selectively transformed through suitable treatments. Nanoparticles of EU3+-doped YAG (yttrium aluminum garnet, a mixed ceramic oxide ) self-assembled on this patterned silicon substrate. These particles emit photons in the visible spectrum at room temperature when excited by a laser. The emission from these nanoparticles is stable and does not undergo any photobleaching effects.
Read the full article on the Nanowerk website.
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By Michael Berger, Copyright 2006 Nanowerk LLC