1.59 µm room temperature emission from metamorphic InAs/InGaAs quantum dots grown on GaAs substrates

We present design, preparation by molecular beam epitaxy, and characterization by photoluminescence of long-wavelength emitting, strain-engineered quantum dot nanostructures grown on GaAs, with InGaAs confining layers and additional InAlAs barriers embedding InAs dots. Quantum dot strain induced by metamorphic lower confining layers is instrumental to redshift the emission, while a-few-nanometer thick InAlAs barriers allow to significantly increase the activation energy of carriers' thermal escape. This approach results in room temperature emission at 1.59 µm and, therefore, is a viable method to achieve efficient emission in the 1.55 µm window and beyond from quantum dots grown on GaAs substrates.