The effect of atomic interdiffusion in InGaAsSb/AlGaAsSb quantum wells grown onto a GaSb substrate was modelled. The material modification after interdiffusion was calculated using Fick’s second law of diffusion and the rationalized biquadratic quinary interpolation algorithm. The results showed that both the group-III and group-V atomic interdiffusions lead to blue-shifts of ground-state transition energies. For identical diffusion lengths, the group-III interdiffusion produces a larger ground-state blue-shift than the group-V interdiffusion. A wavelength blue-shift as large as 772nm was predicted from a 10-nm-wide interdiffused quantum well with an identical diffusion length of 5nm for both the group-III and group-V sub-lattices. The large wavelength tuning range indicated that the interdiffusion method could be potentially used to trim the emission wavelengths of InGaAsSb/AlGaAsSb quantum-well structures for various mid-infra-red-based photonics devices. The present results were also expected to serve as useful references for better process control of the epitaxial growth of Sb-based systems.

Interdiffusion in InGaAsSb/AlGaAsSb Quantum Wells. Y.Wang, H.S.Djie, B.S.Ooi: Journal of Applied Physics, 2005, 98[7], 073508 (7pp)