Properties of Bi<sub>2</sub>Se<sub>3</sub> and Bi<sub>x</sub>Sb<sub>(2-x)</sub>Te<sub>3</sub> grown by MBE
ORAL
Abstract
We have studied molecular beam epitaxy growth of Bi2Se3 and BixSb(2-x)Te3. We have demonstrated that by using a two-step growth recipe, very flat films of both materials can be obtained. The film quality was confirmed using RHEED oscillations during growth and, post-growth XRD, AFM, and STEM. Under other growth and processing conditions, we have observed a more complicated film morphology in the growth of BixSb(2-x)Te3, which we attribute to compositional phase segregation. Using different substrates strongly impacts the film morphology. By tuning the ratio of Bi to Sb, the carrier type can be tuned from p-type to n-type measured via the Hall effect. The films were also studied by ARPES using a flip-chip cleaving approach in which the film plane at the interface to the substrate is measured after cleaving. The Hall and ARPES results agreed with regard to carrier type.
*This work is supported by the National Science Foundation.
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Presenters
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Yang Bai
- University of Illinois at Urbana-Champaign
- Physics, University of Illinois at Urbana-Champaign
- Department of Physics, University of Illinois-Urbana-Champaign