GaSb quantum rings grown by metal organic molecular beam epitaxy

Abstract

GaSb quantum rings (QRs) of different sizes and shapes were grown by metal organic molecular beam epitaxy (MOMBE). Partially capped InAs quantum dots (QDs) grown on a GaAs buffer layer were flattened by In-flushing, followed by regrowth of GaSb which forms ring structure around the InAs seed dots. With the assistance of such an InAs/GaAs groundwork layer, the GaSb QRs exhibit a better defined shape compared to the spontaneously formed rings. First, rims of QRs develop around the boundary of the InAs/GaAs, then additional GaSb QDs grow on top of them preferentially along the [0−11] direction compared to [011].