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Metalorganic chemical vapor deposition- and molecular beam epitaxy-grown strain-balanced InAs/InAs1-xSbx type-II superlattices with 20-100 periods and Sb composition between 0.22≤x≤0.30 exhibit photoluminescence between 5.8 to 10.6 μm at 5 K. The temperature dependent onset of photoresponse obtained from photoconductivity measurements is fit to the Varshni equation, resulting in fitting parameters closer to those of InAs than InSb, and the Fan expression, which gives a Debye temperature less than that of InAs or InSb. [ABSTRACT FROM AUTHOR]

The effects of the strain-compensation (SC) layers in multiple-stack quantum dot (QD) structures are systematically investigated using InxGa1-xP (0.30<×<0.36). High-resolution x-ray diffraction spectra quantify the overall strain in each sample and indicate > 35% strain reduction can be accomplished. Transmission electron microscope and atomic force microscope reveal that the SC layers reduce defect density and improve QD uniformity compared to uncompensated QD stacks. The SC layer increases room temperature photoluminescence (λ=1.34 μm) intensity for a 5-stack QD active region by one order of magnitude. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]