Details on compositional and structural analysis using AES, XRD, AFM, and RHEED, complete datasets of XRD, AFM, and REELS measurements, a comparison of the in-plane strain parameters with (100) β-(AlxGa1−x)2O3 thin films, and energy level diagram of (100) β-Ga2O3/β-(Sc0.17Ga0.83)2O3 heterojunction.