Defects In (111) HgTe Grown By Molecular Beam Epitaxy.

Room temperature Hall mobilities of (100) HgTe films grown by molecular beam epitaxy can reach values of 27,000 - 31,000 cm sup 2 V sup(-1), while the mobilities of (111) films are only 14,000 - 16,000 cm sup 2 V sup (-1) sup (-1). We show that the defects which lead to the lower mobilities of (111) films are present in the first 1.000angstroms of growth. Transmission electron microscope studies reveal a cellular structure of high angle grain boundaries with some twinning about the (111) growth axis. These defects, and hence the reduced mobilities of the films, appear to result from island nucleation of the films.