Fabrication
Quantum wells are formed in semiconductors by having a material, like gallium arsenide sandwiched between two layers of a material with a wider bandgap, like aluminium arsenide. These structures can be grown by molecular beam epitaxy or chemical vapor deposition with control of the layer thickness down to monolayers.
(Other example: layer of indium gallium nitride (InGaN) sandwiched between two layers of gallium nitride (GaN). )
Thin metal films can also support quantum well states, in particular, metallic thin overlayers grown in metal and semiconductor surfaces. The electron (or hole) is confined by the vacuum-metal interface in one side, and in general, by an absolute gap with semiconductor substrates, or by a projected band gap with metal substrates.
Read more about this topic: Quantum Well
Famous quotes containing the word fabrication:
“What preoccupies us, then, is not God as a fact of nature, but as a fabrication useful for a God-fearing society. God himself becomes not a power but an image.”
—Daniel J. Boorstin (b. 1914)
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—Camille Paglia (b. 1947)
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—Jerome K. Jerome (1859–1927)