Stability of low-carrier-density topological-insulator Bi{sub 2}Se{sub 3} thin films and effect of capping layers
- Department of Materials Science and Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 (United States)
- Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854 (United States)
- Department of Physics and Astronomy, The Institute for Quantum Matter, The Johns Hopkins University, Baltimore, Maryland 21218 (United States)
Although over the past number of years there have been many advances in the materials aspects of topological insulators (TIs), one of the ongoing challenges with these materials is the protection of them against aging. In particular, the recent development of low-carrier-density bulk-insulating Bi{sub 2}Se{sub 3} thin films and their sensitivity to air demands reliable capping layers to stabilize their electronic properties. Here, we study the stability of the low-carrier-density Bi{sub 2}Se{sub 3} thin films in air with and without various capping layers using DC and THz probes. Without any capping layers, the carrier density increases by ∼150% over a week and by ∼280% over 9 months. In situ-deposited Se and ex situ-deposited poly(methyl methacrylate) suppress the aging effect to ∼27% and ∼88%, respectively, over 9 months. The combination of effective capping layers and low-carrier-density TI films will open up new opportunities in topological insulators.
- OSTI ID:
- 22499238
- Journal Information:
- APL Materials, Vol. 3, Issue 9; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 2166-532X
- Country of Publication:
- United States
- Language:
- English
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