“…More details of the experimental conditions can be found elsewhere. 10,15,20 After MBE growth, the structures were characterized by atomic force microscopy (AFM), TEM, and high-resolution x-ray diffraction (HRXRD). In addition, van der Pauw and Hall-effect measurements were performed at temperatures ranging from room-temperature (RT) to 20 K. The dominant type of carrier in the structures was determined by applying a magnetic field up to 1.3 kG.…”