Nanocrystal
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Fahlman, B. D. has described a nanocrystal as any nanomaterial with at least one dimension ≤ 100nm and that is singlecrystalline.[1] More properly, any material with a dimension of less than 1 micrometre, i.e., 1000 nanometers, should be referred to as a nanoparticle, not a nanocrystal. For example, any particle which exhibits regions of crystallinity should be termed nanoparticle or nanocluster based on dimensions. These materials are of huge technological interest since many of their electrical and thermodynamic properties show strong size dependence and can therefore be controlled through careful manufacturing processes.
Crystalline nanoparticles are also of interest because they often provide single-domain crystalline systems that can be studied to provide information that can help explain the behaviour of macroscopic samples of similar materials, without the complicating presence of grain boundaries and other defects. Semiconductor nanocrystals in the sub-10nm size range are often referred to as quantum dots.
Crystalline nanoparticles made with zeolite are used as a filter to turn crude oil onto diesel fuel at an ExxonMobil oil refinery in Louisiana, a method cheaper than the conventional way.
A layer of crystalline nanoparticles is used in a new type of solar panel named SolarPly made by Nanosolar. It is cheaper than other solar panels, more flexible, and claims 12% efficiency. (Conventionally inexpensive organic solar panels convert 9% of the sun's energy into electricity.) Crystal tetrapods 40 nanometers wide convert photons into electricity, but only have 3% efficiency. (Source: National Geographic June 2006)
Better electroluminiscence has been observed in Silicon nanocrystals.[2] [3] Rare earth incorporation in Si nanocrystal has been reported to produce a satisfactory optical gain.
The term NanoCrystal is a registered trademark[4] of Elan Pharma International Limited (Ireland) used in relation to Elan’s proprietary milling process and nanoparticulate drug formulations.
[edit] See also
- Quantum dot
- Nanoparticle
- Nanocrystal solar cell
- Nanocrystalline silicon
- Magnetic nanoparticles
- Vapor-Liquid-Solid method
[edit] References
- ^ Fahlman, B. D. Materials Chemistry; Springer: Mount Pleasant, MI, 2007; Vol. 1, pp 282–283.
- ^ Light Emission from Silicon Nanocrystals - Size Does Matter ! { Robert G. Elliman et al.
- ^ P.M. Fauchet et al. / Optical Materials 27 (2005) 745–749
- ^ See for example US TM Reg. Nos. 2386089 / 2492925 and EU CTM Reg. No. 000885079
