Mobility in V-shaped quantum wires due to interface roughness and alloy scattering

Abstract

The low temperature mobility in V-shaped AlGaAs/GaAs quantum wires is theoretically investigated. The energy eigenstates and the eigenvalues of the system under study are calculated using a finite difference method. The cartography of the interface allows for realistic values of the rms value of the roughness fluctuations in depth and the autocorrelation length. For one subband occupation we calculate the screened and the unscreened mobility due to the interface roughness scattering. The corresponding mobility exhibits ultrahigh values. We also evaluate the mobility due to alloy scattering. The interface roughness turns out to be the dominant scattering mechanism. When the second electronic subband becomes populated, we investigate the intrasubband and intersubband scattering due to interface roughness, taking into account or excluding screening effects. Comparison is made with other reports.

Mobility limited by cluster scattering in ternary alloy quantum wires

“…In the model of interface roughness, the roughness is treated as "islands" formed at the interface and the autocorrelation length can be interpreted as the island extent. [37] Similarly, the autocorrelation length Λ in our model can also be regarded as the extent of clusters. The potential of cluster scattering results from both the short-range repulsive effect and the long-range Coulomb effect generated by the trapped electrons.…”

“…When screening effect is taken into consideration, the scattering matrix elements H k k should be replaced by H k k /ε(q) with ε(q) being the 1D dielectric function. Under the random-phase approximation (RPA), ε(q) can be expressed in terms of the form factor F(q) and the statistic polarizability Π (q) at given temperature T , namely, [37,41] ε(q) = 1 + F(q)Π (q, E F ).…”

Formation mechanism of homo-epitaxial morphology on ZnO (000 ± 1) polar surfaces

“…For instance, the interface roughness has an important influence on the carrier mobility in homo-and hetero-junction electronic devices. 7,8 The smoothness of crystal surface also determines the quality of F-P cavity in the electrically pumped laser. 9 However, there is limited success on precisely controlling the properties of ZnO crystals, although great efforts have been made over the past years.…”

Οπτικές Ιδιότητες Και Ιδιότητες Μεταφοράς Κβαντικών Συρμάτων Σχήματος V

“…Sto tètarto keflaio parousizoume thn prwtìtuph jewrhtik mac melèth [37] pou afor thn EukinhsÐa QWRs sq matoc V Diereuntai h eukinhsÐa se qamhlèc jermokrasÐec QWRs, apallagmènwn prosmÐxewn, diatom c sq matoc V lambnontac upìyh touc dÔo kurÐarqouc mhqanismoÔc skèdashc. AutoÐ eÐnai h skèdash exaitÐac thc endoepifaneiak c traqÔthtac kai exaitÐac ataxÐac krmatoc.…”

“…Sth sunèqeia parousizoume thn prwtìtuph ergasÐa mac [37] pou diereun th sumperifor se qamhlèc jermokrasÐec thc eukinhsÐac se AlGaAs/GaAs QWRs sq matoc V lambnontac upìyh touc kurÐarqouc autoÔc mhqanismoÔc skèdashc.…”