Carrier transport and luminescence in inverted-pyramid quantum structures

Cathodoluminescence spectroscopy and wavelength-dispersive imaging were emp loyed for investigating the carrier transport and recombination in GaAs/AlG aAs inverted-pyramid quantum dot (QD) heterostructures grown on patterned ( 111)B GaAs substrates. The spectra and images clearly evidence carrier reco mbination in quantum wells and quantum wires (QWR) and show potential varia tions in these structures. Luminescence from the lens-shaped QDs was identi fied and characterized as a function of the GaAs layer thickness. Furthermo re, we show a tapering of the GaAs QWR that self-forms at the corners of th e pyramids. Application of such tapered QWRs as "exciton accelerators" is d iscussed. (C) 2000 American Institute of Physics. [S0003-6951(00)04350-3].