MBE InAs quantum dots grown on metamorphic InGaAs for long wavelength emitting

GaAs-based InAs quantum dots using InGaAs composition-graded metamorphic layers have been investigated by molecular beam epitaxy. Emission with the wavelength ∼1.5 μm from the dots was obtained at room temperature with the relatively large full width at half maximum. The emission wavelength is relatively stable when subjected to fast annealing. The number density of dots reached ∼6×1010 cm−2. Undulated morphology was observed on the surface of the sample, which has some influence on the dot size and distribution. In epilayers, misfit dislocations were confined within the step-graded InGaAs metamorphic buffer layer.