The application of an InGaAs/GaAsN strain-compensated superlattice to InAs quantum dots

Application of InGaAs/GaAsN strain-compensated superlattice (SCSL) to InAs quantum dots (QDs) has been studied with atomic force microscopy (AFM), reflection high-energy electron diffraction (RHEED), and temperature-dependent photoluminescence (PL) measurements. The insertion of a tensile-strained GaAsN layer between InGaAs layers with high In concentrations can compensate the compressive strain in the InGaAs layers and reduce the flattening of QDs during the growth of the successive InGaAs layers. Compared with QDs capped with a single InGaAs layer of a high In concentration, QDs capped with such SCSLs can achieve almost the same redshift of emission wavelength, while the optical property is highly improved. The mechanism responsible for this is discussed based on the AFM, RHEED, and PL measurements