Cascade theory of electron capture in quantum wells

A cascade theory of electron capture in shallow quantum wells, when the capture process is determined by the interaction with acoustic phonons, is constructed. In these conditions, the ejection of electrons falling into a well back to the conduction band is significant. The possibility of electron ejection is taken into account by introducing an sticking probability for electrons located in the well. Such an approach is analogous to the Lax cascade theory of electron capture at small impurity centers. Calculations have been performed for wells 3 and 4 nm in width in the Al_0.05Ga_0.95As/GaAs/Al_0.05Ga_0.95As heterostructure. The developed theory has also made it possible to describe thermal ejection of electrons from shallow quantum wells.