Strong photoluminescence emission at room temperature of strained InGaAs quantum disks (200–30 nm diameter) self-organized on GaAs (311)B substrates

Abstract

We have recently found that quantum-box-like structures are formed during spontaneous reorganization of a sequence of AlGaAs and strained InGaAs epitaxial films grown on GaAs (311)B substrates by metalorganic vapor-phase epitaxy into InGaAs islands (disks) buried beneath AlGaAs. The size of the disks is directly controlled by the In content in the range 200–30 nm. Strong photoluminescence (PL) efficiency at room temperature is observed in these strained quantum disks. Even for the 30 nm disk the radiative efficiency is not reduced compared to the reference (100) quantum well. The PL spectra are characterized by narrow linewidth and well resolved exciton resonances in excitation spectroscopy.