Nanocrystal

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Most generally, "Nanocrystal" is used to mean a crystalline nanoparticle. Some sources define a nanocrystal as any singlecrystalline nanomaterial with at least one dimension ≤ 100 nm.,[1] while others define it more generally to be a nanoparticle with any kind of crystalline structure [2] [3] including e.g. multiply twinned configurations.

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Summary [edit]

A general material object with all dimensions less than 1 micrometre, i.e., 1000 nanometers, should be referred to as a nanoparticle, not a nanocrystal. In case it is single-crystalline or polycrystalline, it may be referred to as a nanocrystal.[1][2][3]

Crystalline nanoparticles are of interest because of many reasons. Silicon nanocrystals can provide efficient light emission even while bulk Si does not [4] and be used as for memory components.[5] Nanocrystals embedded in solids can exhibit much more complex melting behaviour than conventional solids [6] and can form the basis of a special class of solids .[7] They can also 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[citation needed]. Semiconductor nanocrystals in the sub-10 nm size range are often referred to as quantum dots.

Crystalline nanoparticles made with zeolite are used as a filter to turn crude oil into diesel fuel at an ExxonMobil oil refinery in Louisiana, a method cheaper than the conventional way[citation needed].

A layer of crystalline nanoparticles is used in a new type of solar panel named SolarPly made by Nanosolar.[citation needed] 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)

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References [edit]

  1. ^ a b Fahlman, B. D. Materials Chemistry; Springer: Mount Pleasant, Michigan, 2007; Vol. 1, pp 282–283.
  2. ^ a b Burt, J. L. (2005). "Beyond Archimedean solids: Star polyhedral gold nanocrystals". J. Cryst. Growth 285: 681. 
  3. ^ a b Xu, J (2008). "Hydrothermal syntheses of gold nanocrystals: From icosahedral to its truncated form". Advanced Functional Materials 18: 277. 
  4. ^ Pavesi, Lorenzo (2000). "Optical gain in silicon nanocrystals". Nature 408: 440. 
  5. ^ Tiwari, S. (1996). "A silicon nanocrystal based memory". Appl. Phys. Lett. 68: 1377. 
  6. ^ Pakarinen, J (2009). "Partial melting mechanisms of embedded nanocrystals". Phys. Rev. B 79: 085426. 
  7. ^ Talapin, D. V. (2012). "Nanocrystal solids: A modular approach to materials design". MRS Bulletin 37: 63. 

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