Electron–interface-phonon scattering in graded quantum wells ofGa1−xAl

Abstract

Using the method of series expansion, interface-phonon vibrational modes are calculated in the dielectric continuum model for the graded quantum well of Ga& Al, As with a Gap 6Alp 4As barrier. The intrasubband and intersubband scattering rates are obtained as functions of quantum-well width. The results reveal that the behavior of interface phonon modes is very di8'erent from that in a square quantum-well structure. It is found that the electron -interface-phonon scattering rates can be changed remarkably in a graded quantum-well structure compared with those in a square quantum-well structure, which is usefu1 for some device applications.

Electron-phonon scattering in graded quantum dots

“…By varying the concentration appropriately, one can engineer confining potentials that restrict electron motion in a particular spatial direction. Intentional grading can be used to control the strain in quantum dot structures [1], reduce the electron capture times [2] or modify the electron-phonon scattering [3,8].…”

A surface optical phonon assisted transition in a semi-infinite superlattice with a cap layer

“…It is well known that the electron-optical phonon interactions (EOPIs) in semiconductor heterostructures play a dominant role in determining various electronic properties including mobility, tunnelling and the scattering rate which are much important for device applications. On the basis of the dielectric continuum approach [1], many researchers explored the behaviour and properties of the optical phonon, EOPI in various layered structures such as ionic slab [1], quantum well [2][3][4][5][6][7][8], quantum dot [9], quantum cable [10] and superlattice (SL) [11][12][13][14]. Additionally, the influences of the concentration on the optical and electronic properties and EOPI in quantum wells consisting of a ternary mixed crystal are also studied in detail [15].…”

The evolution of the localized interface optical-phonon modes in a finite superlattice with a structural defect

“…The properties of the localized acoustic modes have been reported in various structures such as infinite SL with a structural defect layer [7][8][9], semi-infinite SL with a substrate or an adsorbed layer [10] and in finite SL [11][12][13][14][15]. Since the interface optical-phonon modes (IOPMs) were found to play a dominant role in electron-phonon interactions in quantum wells and SLs [16][17][18][19][20][21], the properties of the localized and extended IOPMs have been a very interesting subject in SL with the presence of inhomogeneities such as surface, interface or defect layer. The interface optical phonons in an infinite superlattice [22] and in a finite multilayer structure [23] were derived.…”