Characterization of Bi2Te3 and Bi2Se3 topological insulators grown by MBE on (001) GaAs substrates
(Color online) RHEED intensity of the specular point vs growth time under different Bi cell temperatures: (a) Bi2Te3 and (b) Bi2Se3. Inset: RHEED patterns observed for direction of the GaAs (001) substrate during MBE growth of: (a) Bi2Te3 and (b) Bi2Se3.
(Color online) AFM images of Bi2Te3 and Bi2Se3 samples grown with the Te2/Bi BEP ratio of ten and Se2/Bi BEP ratio of 20, respectively. (a) 210-nm-thick Bi2Te3; (b) 215-nm-thick Bi2Se3; (c) 15-nm-thick Bi2Te3; (d) 15-nm-thick Bi2Se3.
X-ray diffraction data obtained for a 220-nm-thick Bi2(TeSe)3 film grown on a GaAs (001) substrate. The (003) family of reflections are labeled, together with (002) and (004) reflections from the GaAs (001) substrate. Inset: QL thicknesses d QL calculated from XRD data for a series of Bi2(TeSe)3 films plotted as a function of Te2/(Te2 + Se2) BEP ratio. The curve is a guide for the eye.
(Color online) Representative Raman maps (the position differences of the Raman peak E2 g) measured within a scan area of 15 μm × 15 μm for (a) 136 nm thick Bi2Te3 and (b) 150 nm thick Bi2Se3. The unit for the scale bars is cm−1.
High-resolution transmission electron microscopy images showing cross sections of topological insulator (a) Bi2Te3 and (b) Bi2Se3 grown by MBE on a GaAs (001) substrate. The distances between QLs (∼1 nm) are shown as “I.”
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