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Molecular beam epitaxy growth of topological insulator Bi4Br4 on silicon for the infrared applications.
- Source :
- Quantum Frontiers; 8/22/2024, Vol. 3 Issue 1, p1-11, 11p
- Publication Year :
- 2024
-
Abstract
- Bi<subscript>4</subscript>Br<subscript>4</subscript> is a material rich in intriguing topological properties. Monolayer Bi<subscript>4</subscript>Br<subscript>4</subscript> film exhibits helical edge states characteristic of a quantum spin Hall insulator, while bulk Bi<subscript>4</subscript>Br<subscript>4</subscript> represents a higher-order topological insulator with hinge states. However, direct exfoliation from single crystal can only obtain thin nanowires due to the weak van der Waals forces between Bi<subscript>4</subscript>Br<subscript>4</subscript> chains, which limits its optical analysis and application, while the growth of Bi<subscript>4</subscript>Br<subscript>4</subscript> thin films is also full of challenges due to the extremely narrow growth temperature range and the accurate control of the BiBr<subscript>3</subscript> flux. Here, we reported the controlled growth of α-Bi<subscript>4</subscript>Br<subscript>4</subscript> thin films on intrinsic silicon substrates using molecular beam epitaxy. The growth temperature, BiBr<subscript>3</subscript> flux, and the flux ratio of Bi and BiBr<subscript>3</subscript> were accurately controlled. Then, the morphology, composition, and bonding of the prepared films were investigated using atomic force microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy. The growth of large, uniform thin films provides an ideal material platform for studying the physical properties of Bi<subscript>4</subscript>Br<subscript>4</subscript>. Additionally, we utilized Fourier-transform infrared spectroscopy to explore the film's infrared characteristics, revealing strong absorption in the low frequency range due to the high proportion of one-dimensional topological edge states and laying the groundwork for further exploration of its potential applications in the optoelectronic field. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 27316106
- Volume :
- 3
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- Quantum Frontiers
- Publication Type :
- Academic Journal
- Accession number :
- 179165878
- Full Text :
- https://doi.org/10.1007/s44214-024-00062-4