Time-resolved cathodoluminescence study of carrier relaxation in GaAs/ AlGaAs layers grown on a patterned GaAs(001) substrate
نویسندگان
چکیده
We have examined the kinetics of carrier relaxation in three-dimensionally confined GaAs/AlGaAs layers obtained by growth on prepatterned GaAs~001! with time-resolved cathodoluminescence ~CL!. Time-delayed CL spectra at 87 K reveal that ~i! relaxation of hot carriers into the largest 3D confined regions occurs on a time scale of a few hundred ps during the onset of luminescence, and ~ii! the luminescence decay time also increases for these larger confined regions, owing to thermal reemission from QWs, diffusion across AlxGa12xAs barriers, and carrier feeding from surrounding thinner QWs. © 1996 American Institute of Physics. @S0003-6951~96!04331-8#
منابع مشابه
Carrier relaxation and recombination in GaAs/AlGaAs quantum heterostructures and nanostructures probed with time-resolved cathodoluminescence
We have examined the kinetics of carrier relaxation in GaAs/AlGaAs quantum wells ~QWs!, quantum wires ~QWRs!, and quantum boxes ~QBs! with time-resolved cathodoluminescence ~CL!. In the cases of QWRs and QBs, the nanostructures were grown via a size-reducing growth approach on pre-patterned GaAs~001! substrates composed of stripes and mesas, respectively. The growth involved deposition of multi...
متن کاملInfluence of GaAs(001) substrate misorientation towards ˆ111‰ on the optical properties of InxGa12xAs/GaAs
Local variations in the optical properties of thick In0.13Ga0.87As films grown on GaAs~001! substrates misoriented toward $111% planes have been studied with polarized and spectrally-resolved cathodoluminescence ~CL! imaging. The degree of anisotropic relaxation and density of dark line defects ~DLDs! in CL was found to depend on the choice of the substrate miscut orientation. An enhanced aniso...
متن کاملGrowth controlled fabrication and cathodoluminescence study of 3D confined GaAs volumes on non-planar patterned GaAs(0 0 1) substrates
We report on (a) the effect of growth interruption on the growth profile evolution in growth on non-planar patterned mesa tops via substrate-encoded size-reducing epitaxy (SESRE) and (b) the optical behavior of isolated 3D-confined GaAs volumes as well as 3D-confined GaAs volumes coupled with 1D-confined quantum wells (QWs) fabricated by SESRE. Steady-state excitation and time-resolved cathodol...
متن کاملInfluence of various growth parameters on the interface abruptness of AlAs/GaAs short period superlattices
Cross-sectional scanning tunneling microscopy has been used to investigate the effects of several key growth parameters on the resulting interfacial quality of AlAs/GaAs short period superlattices. For growth on top of AlGaAs layers, only superlattices grown with periodicity no smaller than 4 unit cells of GaAs and 2 unit cells of AlAs and grown with a minimum of 30 s of growth interrupt time a...
متن کاملCathodoluminescence study of disordering of GaAs/AlGaAs quantum wells using an AlAs native oxide and thermal annealing technique
GaAs/AlGaAs quantum wells ~QWs!, selectively disordered using an AlAs native oxide and thermal annealing technique, were studied using spectrally, spatially, and temporally resolved cathodoluminescence ~CL!. The spectral shift of the QW luminescence was determined as a function of annealing temperature in the oxide and nonoxide regions. Time-resolved CL was used to assess the impact of defects ...
متن کامل