The optimized growth conditions and evidence for type-II alignment in GaAsSb/InGaAs heterostructures are reported. The asymmetric GaAsSb/InGaAs bilayer quantum well grown on GaAs shows promising results for device applications around the wavelength of 1.3 mum. Uncompensated type-II GaAs/GaAsSb/GaAs quantum-well systems and strain-compensated GaAsP/GaAs/GaAsSb/GaAs/GaAsP quantum-well systems are compared for 1.3 mum applications. Inhomogeneous photoluminescence-linewidth broadening due to lateral composition and thickness variation is reduced from 74 to 40 meV when GaAsP strain-compensation layers are added to GaAsSb-based trilayer quantum-well systems,