Transport studies of GaAs1−xSbx-AlyGa1−yAs strained-layer superlattices

Abstract

Electrical transport in modulation-doped GaAs1−xSbx-AlyGa1−yAs strained-layer superlattices (SLS) grown by molecular beam epitaxy was studied, using low field Hall measurements from 4.2 to 300 K, high field quantum transport, and the far-infrared cyclotron resonance at 4.2 K. Our results show directly a degenerate two-dimensional electron gas in the SLS with an effective mass m*=0.063m0 and a mobility μ=7.7×103 cm2/Vs at a density ns =6.7×1011 cm−2, demonstrating the feasibility of high quality GaAs1−xSbx-AlyGa1−yAs SLS with good two-dimensional electronic transport properties despite the large lattice mismatch between the constituent layers.