Interface roughness scattering in InAs/AlSb quantum wells

We present a study of interface roughness scattering in not‐intentionally‐doped AlSb/InAs/AlSb quantum wells grown by molecular beam epitaxy on [001] GaAs semi‐insulating substrates. The low‐temperature mobility is found to be limited by interface roughness scattering for well widths below 100 A. The measured mobilities are well accounted for by Gold’s theoretical treatment [A. Gold, Phys. Rev. B 35, 723 (1987)], once it is suitably modified to account for the band nonparabolicity of InAs. The experimental electron density dependence of the mobility indicates a lateral correlation length for the interface roughness Λ≊62 A for interface fluctuations approximately 1 monolayer high. We believe this roughness scale is characteristic of the bottom (InAs‐on‐AlSb) interface.

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