Free versus localized exciton in GaAs V-shaped quantum wires

Abstract

Exciton localization in In 0.15 Ga 0.85 As/GaAs quantum wire structures grown on (553)B-oriented GaAs substrate J. Appl. Phys. 90, 5111 (2001); 10.1063/1.1412271 Optical characterization of the self-limiting effect in flow-rate modulation epitaxy of V-shaped GaAs quantum wire Appl. Phys. Lett. 75, 4148 (1999); 10.1063/1.125565Observation of wire width fluctuations in the optical spectra of GaAs-AlGaAs V-groove quantum wires

Localization effects on recombination dynamics in InAs/InP self-assembled quantum wires emitting at 1.5 μm

“…The exciton localization energies deduced for our QWRs, E L % 8-16 meV (Table II), suggest that localization effects would be considerably larger than those reported in the GaAs/AlGaAs system. 19,20 This result can be compared with structural characterization studies: many elongated QWR defects sometimes more than 500 nm long (zones where the height is different than the average) are typically measured by AFM characterization. 12 Along the QWRs, there are also observed width fluctuations extending 100-150 nm in average.…”

“…8,18,19 Among these works, we have selected the model proposed by Lomascolo et al, since through this model, the lifetime evolution with temperature is described by means of parameters representative of our self-assembled QWRs. 20 In fact, fitting the data in Fig. 4 to the next expression we are going to estimate the localization energy and density of localization centers of the QWRs studied in the present sample: Given that M can be slightly different for excitons in InAs QWRs (due to a different valence band mixing), our results should be taken for a realistic, but semi-quantitative discussion.…”

Near-field low-temperature photoluminescence spectroscopy of single V-shaped quantum wires

“…In particular, structures based on In x Ga 1Ϫx As are interesting candidates for applications in optical communications and model systems for studying the impact of the two-dimensional quantum confinement on the fundamental optical and electronic properties of 1D semiconductor nanostructures. [2][3][4][5] Much of the information on the optical and electronic properties of V-QWRs has been obtained from photoluminescence studies. In such experiments, the distance between adjacent V-QWRs ͑typically between 0.5 and 1 m͒ is generally smaller than the achieved spatial resolution, leading to the investigation of ensembles of up to 100 nanostructures.…”

Observation of combined electron and photon confinement in planar microcavities incorporating quantum wires

“…12,17 No such fundamental polarization selection rule exists for similar bulk or QW emitters. The low temperature inhomogeneous broadening of the emission, brought about by exciton localization at QWR disorder potential minima, 12,18 results in a ratio of about 10 between the QWR emission FWHM and the cavity mode FWHM. As a consequence, one can use the cavity mode as a …”