Two-dimensional X-ray diffraction characterization of (Zn,Cd,Mg)Se wurtzite layers grown on Bi2Se3

Abstract

The wurtzite structure of ZnSe, Zn 0.49 Cd 0.51 Se and Zn 0.23 Cd 0.25 Mg 0.52 Se layers grown on Bi 2 Se 3 /sapphire (0001) by Molecular Beam Epitaxy (MBE) is reported. Structure characterization is studied by two-dimensional X-ray diffraction. Pole figures are calculated for cubic and hexagonal planes of the (Zn,Cd,Mg)Se family and compared to their expected values. The targeted wurtzite plane was (11-22), while the cubic ones were the (220) and (311). The results show that, under our MBE growth conditions, ZnSe, Zn 0.49 Cd 0.51 Se and Zn 0.23 Cd 0.25 Mg 0.52 Se layers prefer to form the hexagonal (wurtzite) phase rather than the cubic one when grown on Bi 2 Se 3 /sapphire in (0001) direction. These results have implications for the next generation devices combining semiconductors and topological insulator materials.

Self-assembled Bismuth Selenide (Bi2Se3) quantum dots grown by molecular beam epitaxy

“…This peak is attributed to the growth of grains of wurtzite ZnSe or of misoriented ZnSe on top of the Bi 2 Se 3 QDs by van der Waals epitaxy 36 . Chen 36 and Hernandez-Mainet 35 et al ., described the preferential growth of the wurtzite (hexagonal) phase when ZnCdSe was grown on Bi 2 Se 3 . However, we were unable to find the same described peaks or symmetry in the HR-XRD pattern.…”

“…Zinc Selenide, ZnSe, a wide-gap semiconductor (E g = 2.7 eV), has a very similar lattice parameter as GaAs and it can be grown as a strained layer on GaAs 34 . ZnSe has also been previously grown over Bi 2 Se 3 layers 35 . The ideal temperature for ZnSe epitaxial growth is close to 250 °C, which is the temperature used for the QD growth.…”