Abstract:
The specific features of the emission characteristics of GaAs-based heterostructures with a GaAs$_{1-x}$Sb$_x$–In$_y$Ga$_{1-y}$As bilayer quantum well are studied. The heterostructures are grown by metal-organic chemical vapor deposition (MOCVD). With an analysis of previously reported data on the MOCVD growth process taken into account, the temperature range (560–580$^\circ$C), the relation between the fluxes emitted by the sources of Group-V and -III elements $(\lesssim 1)$, and the order of layer growth for the production of the active region of a GaAs/InGaP laser heterostructure are determined experimentally. The active region is a GaAs$_{0.75}$Sb$_{0.25}$–In$_{0.2}$Ga$_{0.8}$As bilayer quantum well. For the structure, a 1075-nm electroluminescence signal attributed to indirect transitions between the valence band of the GaAs$_{0.75}$Sb$_{0.25}$ layer and the conduction band of the In$_{0.2}$Ga$_{0.8}$As layer is observed. An increase in the continuous-wave pump current yields a decrease in the 1075-nm emission intensity and initiates stable lasing at a wavelength of 1022 nm at a threshold current density of 1.4 kA cm$^{-2}$ at room temperature. Lasing occurs at transitions direct in coordinate space.
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