Abstract
The optical quality enhancement of a GaAs template grown on Silicon substrate using InGaAs/GaAs Dislocation Filters (DFs) combined with an annealing step have been assessed optically using Photoluminescence (PL) of embedded InAs/InGaAs QDs within a GaAs matrix. An annealing temperature after the growth of the DFs of 690 degrees C was shown to be optimum, giving an enhanced PL emission from the embedded InAs QDs in terms of intensity and Full Width at Half Maximum (FWHM). InAs quantum dots capped with GaAsSb grown at different temperatures were grown on the optimized GaAs template on Si. The prepared samples were characterized by PL, Atomic Force Microscopy (AFM), excitation power and dependent PL at 77 K and 300 K. At 77 K, the InAs/GaAsSb grown at 484 degrees C showed a type II band alignment with an emission wavelength of 1297 nm, which is shorter than the emission obtained from the reference sample, where the GaAsSb-capped dots were grown on GaAs (1357 nm). By reducing the GaAsSb capping layer growth temperatures to 465 degrees C and 450 degrees C, the wavelength at 77 K was extended to 1375 nm and 1480 nm respectively, resulting from an increased Sb content in the capping layer. At 300 K, a long wavelength emission of 1623 nm have been achieved. (C) 2018 Elsevier B.V. All rights reserved.