A nanocrystal is a material particle having at least one dimension smaller than 100 nanometres, based on quantum dots |author=J. L. Burt |year=2005 |title=Beyond Archimedean solids: Star polyhedral gold nanocrystals |journal=J. Cryst. Growth |volume=285 |pages=681 |doi=10.1016/j.jcrysgro.2005.09.060 }} The size of nanocrystals distinguishes them from larger crystals. For example, silicon nanocrystals can provide efficient light emission while bulk silicon does not When embedded in solids, nanocrystals may exhibit much more complex melting behaviour than conventional solids Semiconductor nanocrystals having dimensions smaller than 10 nm are also described as quantum dots.
SynthesisThe traditional method involves molecular precursors, which can include typical metal salts and a source of the anion. Most semiconducting nanomaterials feature chalcogenide (SS−, SeS−, TeS−) and pnicnides (P3−, As3−, Sb3−). Sources of these elements are the silylated derivatives such as bis(trimethylsilyl)sulfide (S(SiMe3)2 and tris(trimethylsilylphosphine (P(SiMe3)3). Some procedures use surfactants to solubilize the growing nanocrystals. In some cases, nanocrystals can exchange their elements with reagents through atomic diffusion.
ApplicationsNanocrystals made with zeolite are used to filter crude oil onto diesel fuel at an ExxonMobil oil refinery in Louisiana at a cost less than conventional methods.
- Cadmium telluride nanocrystals
- Magnetic nanoparticles
- Nanocrystal solar cell
- Nanocrystalline silicon
- Quantum dot