Suppression of bulk conductivity and large phase relaxation length in topological insulator Bi2-δSnδTe3 epitaxial thin films grown by Metal-Organic Chemical Vapor Deposition (MOCVD)
| Autor: | Seong Keun Kim, Kwang-Chon Kim, Seong Won Cho, Suyoun Lee, Byung-ki Cheong, Jinsang Kim |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
Condensed matter physics Magnetoresistance Mechanical Engineering Metals and Alloys 02 engineering and technology Chemical vapor deposition 021001 nanoscience & nanotechnology 01 natural sciences Mechanics of Materials Topological insulator Phase (matter) 0103 physical sciences Materials Chemistry Metalorganic vapour phase epitaxy Thin film 010306 general physics 0210 nano-technology Electronic band structure Surface states |
| Zdroj: | Journal of Alloys and Compounds. 723:942-947 |
| ISSN: | 0925-8388 |
| Popis: | A topological insulator (TI), a new quantum state featured with the topologically-protected surface state (TSS) originating from its unique topology in band structure, has attracted much interest due to academic and practical importance. Nonetheless, a large contribution of the bulk conduction, induced by unintended doping by defects, has hindered the characterization of the surface state and the application of it into a device. To resolve this problem, we have investigated the transport properties of epitaxial Bi 2-δ Sn δ Te 3 thin films with varying δ. With the bulk conduction being strongly suppressed, the TSS is separately characterized, resulting in a large phase relaxation length of ∼250 nm at 1.8 K. In addition, the magnetoresistance ratio (MR) has shown a non-monotonic temperature dependence with a maximum value at an elevated temperature depending on δ. These results are associated with the compensation of carriers and, we believe, provide an important step for the application of topological insulators for developing novel functional devices based on the topological surface states. |
| Databáze: | OpenAIRE |
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