Fano resonance study in impurity photocurrent spectra of bulk GaAs and GaAs quantum wells doped with shallow donors

Abstract

The results of theoretical and experimental study of the impurity photocurrent peaks in the spectral region corresponding to the longitudinal optical phonon energy in bulk GaAs and GaAs quantum wells doped with silicon are presented. The general expression to describe these impurity photocurrent peaks is derived. It is shown that the suggested theory adequately describes the impurity photocurrent peaks observed in bulk GaAs. We demonstrate that the photocurrent peak width in a quantum well structure is greater than that in a bulk semiconductor.

Fano resonances in nanoscale structures

“…Asymmetric lineshapes were also observed in Raman spectra of heavily doped semiconductors (Bechstedt and Peuker, 1975;Bell et al, 1973;Cerdeira et al, 1973a;Chandrasekhar et al, 1978;Hopfield et al, 1967;Magidson and Beserman, 2002) and high-T c superconductors (Friedl et al, 1990;Limonov et al, 1998Limonov et al, , 2000Misochko et al, 2000). Although, almost any asymmetric profile of these spectra can be fitted by the Fano formula (Aleshkin et al, 2007;Belitsky et al, 1997;Cardona, 1983;Cardona et al, 1974;Cerdeira et al, 1973b;Hase et al, 2006b;Jin and Xu, 2007;Jin et al, 2001;Menéndez and Cardona, 1985), a suitable theory for a quantitative description of these cases is still lacking. The general qualitative understanding is that the absorbed photon can initiate two kinds of processes.…”

Investigating the phonon line shapes of TMDs: An analytical approach

“…The BWF interference effect involving the interactions of discrete phonon states and the electronic continuum has been studied extensively in carbon-based materials (graphite, graphene, and nanotubes) [49][50][51] and semiconductors. [52][53][54][55] However, there are limited reports of this effect in TMDs. This electron-phonon interaction effect manifests itself as an asymmetric broadening in the phonon line shape depending on the dopant (p-doped or n-doped) and is described by the asymmetric parameter (1/q BWF ).…”

“…Extensive research has been reported on doped porous silicon 55,59,60 and other bulk semiconducting materials. 52,53 Recently, the effect of doping on the electronic transport and phonon line shapes of TMDs has been reported experimentally 56,61,62 and theoretically. 57 Analysis of the phonon line shapes from these reports 56,57,61,62 suggests a linear dependence of the BWF asymmetric parameter (1/q BWF ) on concentration C conc.…”

“…The BWF interference effect involving the interactions of discrete phonon states and the electronic continuum has been studied extensively in carbon‐based materials (graphite, graphene, and nanotubes) 49–51 and semiconductors 52–55 . However, there are limited reports of this effect in TMDs.…”

“…It is known that the BWF asymmetric parameter is dependent on carrier concentration. Extensive research has been reported on doped porous silicon 55,59,60 and other bulk semiconducting materials 52,53 . Recently, the effect of doping on the electronic transport and phonon line shapes of TMDs has been reported experimentally 56,61,62 and theoretically 57 .…”