Interdiffusion in InGaAsSb/AlGaAsSb quantum wells

We modeled the effect of atomic interdiffusion in InGaAsSb/AlGaAsSb quantum well grown on GaSb substrate. The material modification after interdiffusion has been calculated using Fick’s second law of diffusion and the rationalized biquadratic quinary interpolation algorithm. Our results show that both the group-III and group-V atomic interdiffusions lead to blueshifts of ground-state transition energies. For identical diffusion lengths, the group-III interdiffusion produces a larger ground-state blueshift than the group-V interdiffusion. A wavelength blueshift as large as 772 nm is predicted from a 10-nm-wide interdiffused quantum well with an identical diffusion length of 5 nm for both the group-III and group-V sublattices. The large wavelength tuning range indicates that the interdiffusion method can be potentially used to trim the emission wavelengths of InGaAsSb/AlGaAsSb quantum-well structures for various mid-infrared-based photonics devices. Our results will also serve as useful references for a better process control of the epitaxial growth of Sb-based systems.