1.6 Mu M Emission From Inas Quantum Dots Grown On A Gaas Substrate Using An Algaassb Metamorphic Buffer

We report 1.6 mum emission from InAs QDs (QDs) grown on a GaAs substrate. The ensemble is grown on a graded digital alloy (DA), which increases the matrix lattice constant from 5.65 Angstrom to 5.77 Angstrom. The reduced lattice mismatch between the InAs and matrix material produces larger QDs and thereby allows longer wavelength emission compared to standard growth techniques. The resulting QD density ranges from 2x10(10) to 8 x 10(10)/cm(2) with QD dimensions of 5nm x 30nm measured using atomic force microscopy (AFM). According to x-ray diffraction (XRD) data and transmission electron microscopy (TEM), the metamorphic buffer is unstrained with low defect density.