Emission properties of heterostructures with a (GaAsSb-InGaAs)/GaAs bilayer quantum well

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°C), the relation between the fluxes emitted by the sources of Group-V and ?III elements (?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_0.75Sb_0.25-In_0.2Ga_0.8As bilayer quantum well. For the structure, a 1075-nm electroluminescence signal attributed to indirect transitions between the valence band of the GaAs_0.75Sb_0.25 layer and the conduction band of the In_0.2Ga_0.8As 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.