Carrier mobility as a function of carrier density in type-II InAs/GaSb superlattices

We report on a study of the in-plane carrier mobility in InAs/GaSb superlattices as a function of carrier density. Instead of using a number of differently doped samples, we use the persistent-photoconductivity effect to vary the carrier density over a wide range from n- to p-type in single samples and perform Hall effect measurements. Hence, our data are not obscured by sample to sample nonuniformities. We demonstrate that low-temperature in-plane mobilities are limited by screened interface roughness scattering (IRS), although present models of two-dimensional carrier screening of IRS lead to a limited agreement with our data.