A
quantum
well is a potential well that confines particles,
which were originally free to move in three dimensions, to two dimensions,
forcing them to occupy a planar region. The effects of quantum confinement take place when the quantum well thickness becomes comparable at the de
Broglie wavelength
of the carriers (generally electrons
and holes), leading to energy
levels called "energy
subbands", i.e., the carriers can only have discrete energy values.
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