Abstract
Functional nanocrystals are widely considered as novel building blocks for nanostructured materials and devices. Numerous synthesis approaches have been proposed in the solid, liquid and gas phase. Among the gas phase approaches, low pressure nonthermal plasmas offer some unique and beneficial features. Particles acquire a unipolar charge which reduces or eliminates agglomeration; particles can be electrostatically confined in a reactor based on their charge; strongly exothermic reactions at the particle surface heat particles to temperatures that significantly exceed the gas temperature and facilitate the formation of high quality crystals. This paper discusses two examples for the use of low pressure nonthermal plasmas. The first example is that of a constricted capacitive plasma for the formation of highly monodisperse, cubic-shaped silicon nanocrystals with an average size of 35 nm. The growth process of the particles is discussed. The silicon nanocubes have successfully been used as building blocks for nanoparticle-based transistors. The second example focuses on the synthesis of photoluminescent silicon crystals in the 3-6 nm size range. The synthesis approach described has enabled the synthesis of macroscopic quantities of quantum dots, with mass yields of several mg/hour. Quantum yields for photoluminescence as high as 67% have been achieved.
Original language | English (US) |
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Pages (from-to) | 39-52 |
Number of pages | 14 |
Journal | Journal of Nanoparticle Research |
Volume | 9 |
Issue number | 1 |
DOIs | |
State | Published - Jan 2007 |
Bibliographical note
Funding Information:This work was supported in part by the National Science Foundation under MRSEC award number DMR-0212302, under NIRT-grant DMI-0304211, grant CTS-0500332 and under IGERT award number DGE-0114372, and by InnovaLight, Inc. We acknowledge Dr. Christopher R. Perrey and Professor C. Barry Carter for support with high-resolution TEM.
Keywords
- Luminescence
- Nanoelectronics
- Plasma reactor
- Silicon nanocrystals