Intense Monochromatic Light Emission from Multiple Nanoscale Twin Boundaries in Indirect-gap AlGaAs Epilayers

Abstract

The optical properties of multiple nanoscale twin boundaries in indirect-gap AlGaAs epilayers were studied. Twin boundaries of Σ3-type, extended on {111}B, were self-organized in an epilayer during the epitaxial growth on an AlGaAs(001) substrate by metal–organic vapor-phase epitaxy. Polarized cathodoluminescence spectroscopy in a transmission electron microscope revealed that a set of parallel twin boundaries arranged at similar intervals of nanometer length emits an intense monochromatic light polarized parallel to the boundaries. The photon energy was tunable by controlling the intervals of the boundaries, without changing the crystal structure and the composition.