Carrier transport and luminescence in inverted-pyramid quantum structures

Abstract
Cathodoluminescence spectroscopy and wavelength-dispersive imaging were employed for investigating the carrier transport and recombination in GaAs/AlGaAs inverted-pyramid quantum dot (QD) heterostructures grown on patterned (111)B GaAs substrates. The spectra and images clearly evidence carrier recombination in quantum wells and quantum wires (QWR) and show potential variations in these structures. Luminescence from the lens-shaped QDs was identified and characterized as a function of the GaAs layer thickness. Furthermore, we show a tapering of the GaAs QWR that self-forms at the corners of the pyramids. Application of such tapered QWRs as “exciton accelerators” is discussed.