Nanocrystal
Encyclopedia
B. D. Fahlman has described a nanocrystal as any nanomaterial with at least one dimension ≤ 100nm and that is singlecrystalline.
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 dot
s.
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)
The term NanoCrystal is a registered trademark of Elan Pharma International Limited (Ireland) used in relation to Elan’s proprietary milling process and nanoparticulate drug formulations.
Summary
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 nanoparticleNanoparticle
In nanotechnology, a particle is defined as a small object that behaves as a whole unit in terms of its transport and properties. Particles are further classified according to size : in terms of diameter, coarse particles cover a range between 10,000 and 2,500 nanometers. Fine particles are sized...
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
Macroscopic
The macroscopic scale is the length scale on which objects or processes are of a size which is measurable and observable by the naked eye.When applied to phenomena and abstract objects, the macroscopic scale describes existence in the world as we perceive it, often in contrast to experiences or...
samples of similar materials, without the complicating presence of grain boundaries
Grain boundary
A grain boundary is the interface between two grains, or crystallites, in a polycrystalline material. Grain boundaries are defects in the crystal structure, and tend to decrease the electrical and thermal conductivity of the material...
and other defects
Crystallographic defect
Crystalline solids exhibit a periodic crystal structure. The positions of atoms or molecules occur on repeating fixed distances, determined by the unit cell parameters. However, the arrangement of atom or molecules in most crystalline materials is not perfect...
. Semiconductor
Semiconductor
A semiconductor is a material with electrical conductivity due to electron flow intermediate in magnitude between that of a conductor and an insulator. This means a conductivity roughly in the range of 103 to 10−8 siemens per centimeter...
nanocrystals in the sub-10nm size range are often referred to as quantum dot
Quantum dot
A quantum dot is a portion of matter whose excitons are confined in all three spatial dimensions. Consequently, such materials have electronic properties intermediate between those of bulk semiconductors and those of discrete molecules. They were discovered at the beginning of the 1980s by Alexei...
s.
Crystalline nanoparticles made with zeolite
Zeolite
Zeolites are microporous, aluminosilicate minerals commonly used as commercial adsorbents. The term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt, who observed that upon rapidly heating the material stilbite, it produced large amounts of steam from water that...
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
Nanosolar
Nanosolar is a developer of solar power technology. Based in San Jose, CA, Nanosolar has developed and commercialized a low-cost printable solar cell manufacturing process. The company started selling panels mid-December 2007, and plans to sell them at around $1 per watt...
. 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
Tetrapod (structure)
In coastal engineering, a Tetrapod is a four-legged concrete structure used as armour unit on breakwaters. The Tetrapod's shape is designed to dissipate the force of incoming waves by allowing water to flow around rather than against it, and to reduce displacement by allowing a random distribution...
40 nanometers wide convert photons into electricity, but only have 3% efficiency. (Source: National Geographic June 2006)
The term NanoCrystal is a registered trademark of Elan Pharma International Limited (Ireland) used in relation to Elan’s proprietary milling process and nanoparticulate drug formulations.
See also
- Cadmium tellurideCadmium telluride photovoltaicsCadmium telluride photovoltaics describes a photovoltaic technology that is based on the use of cadmium telluride thin film, a semiconductor layer designed to absorb and convert sunlight into electricity...
nanocrystals - Magnetic nanoparticlesMagnetic nanoparticlesMagnetic nanoparticles are a class of nanoparticle which can be manipulated using magnetic field. Such particles commonly consist of magnetic elements such as iron, nickel and cobalt and their chemical compounds. While nanoparticles are smaller than 1 micrometer in diameter , the larger microbeads...
- Nanocrystal solar cellNanocrystal solar cellQuantum dot solar cells are an emerging field in solar cell research that uses quantum dots as the photovoltaic material, as opposed to better-known bulk materials such as silicon, copper indium gallium selenide or CdTe. Quantum dots have bandgaps that are tunable across a wide range of energy...
- Nanocrystalline siliconNanocrystalline siliconNanocrystalline silicon , sometimes also known as microcrystalline silicon , is a form of porous silicon. It is an allotropic form of silicon with paracrystalline structure—is similar to amorphous silicon , in that it has an amorphous phase...
- NanoparticleNanoparticleIn nanotechnology, a particle is defined as a small object that behaves as a whole unit in terms of its transport and properties. Particles are further classified according to size : in terms of diameter, coarse particles cover a range between 10,000 and 2,500 nanometers. Fine particles are sized...
- Quantum dotQuantum dotA quantum dot is a portion of matter whose excitons are confined in all three spatial dimensions. Consequently, such materials have electronic properties intermediate between those of bulk semiconductors and those of discrete molecules. They were discovered at the beginning of the 1980s by Alexei...