Effect of strain-compensation in stacked 1.3μm InAs∕GaAs quantum dot active regions grown by metalorganic chemical vapor deposition

Publisher Website
Google Scholar
Abstract
We have introduced tensile layers embedded in a GaAs matrix to compensate compressive strain in stacked 1.3μm InAs quantum dot (QD) active regions. The effects of the strain compensation are systematically investigated in five-stack and ten-stack QD structures where we have inserted InxGa1−xP (x=0.30 or 0.36) layers. High-resolution x-ray diffraction spectra quantify the overall strain in each sample and indicate >35% strain reduction can be accomplished. Both atomic force and transmission electron microscope images confirm that strain compensation improves material crystallinity and QD uniformity. With aggressive strain compensation, room temperature QD photoluminescence intensity is significantly increased demonstrating a reduced defect density.