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Bi2Se3 thin films have grown in popularity as three-dimensional topological insulators with a host of potential applications. While the films themselves have been widely researched, improvements derived from better substrate preparation have lagged. In this study, investigations into the preparation of c-plane sapphire (c-sapphire) substrates and the influence on film quality were done. Analysis on the effects of substrate pretreat by ultra-high vacuum annealing of the substrates, the use of Nano-strip® as an etchant, and high temperature in air anneal of c-sapphire to form a terraced morphology on Bi2Se3 thin film growth were done for this study.
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This content will become publicly available on March 1, 2027
Van der Waals epitaxy of millimeter-domain Bi2Se3
The unique electronic structure of Bi2Se3 makes it appealing not only for studying fundamental topological physics but also for pursuing technological applications that include future electronics, spintronics, and quantum computing. This work uses a chemical vapor deposition approach to synthesize submillimeter domain continuous epitaxial thin films as well as continuous films with preferred orientation and domain sizes ranging up to a millimeter. Atomic force microscopy imaging reveals a terraced pyramid structure with step sizes down to one quintuple layer. We observe that large amounts of deposition on the tube walls from previous growths negatively affect the quality of epitaxy but positively affect grain size due to revaporization of previous growth. Transport measurements and Hikami–Larkin–Nagaoka fits of conductivity versus magnetic field indicate a bulk conducting nature to the film. This work pushes forward the domain size Bi2Se3 films by an order of magnitude, while maintaining the regularly reported doping problems of topological insulators.
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- PAR ID:
- 10698654
- Publisher / Repository:
- AVS
- Date Published:
- Journal Name:
- Journal of Vacuum Science & Technology A
- Volume:
- 44
- Issue:
- 2
- ISSN:
- 0734-2101
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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