Bi2Se3 Growth on (001) GaAs Substrates for Terahertz Integrated Systems

• Main Authors: Liu, Yongchen, Acuna, Wilder, Zhang, Huairuo, Ho, Dai Q, Hu, Ruiqi, Wang, Zhengtianye, Janotti, Anderson, Bryant, Garnett, Davydov, Albert V, Zide, Joshua M. O, Law, Stephanie
• Format: Journal Article
• Language: English
• Published: 04-02-2022
• Subjects: Physics - Materials Science
• DOI: 10.48550/arxiv.2202.02234

Terahertz (THz) technologies have been of interest for many years due to the
variety of applications including gas sensing, nonionizing imaging of
biological systems, security and defense, etc. To date, scientists have used
different classes of materials to perform different THz functions. However, to
assemble an on-chip THz integrated system, we must understand how to integrate
these different materials. Here, we explore the growth of Bi2Se3, a topological
insulator (TI) material that could serve as a plasmonic waveguide in THz
integrated devices, on technologically-important GaAs (001) substrates. We
explore surface treatments and find that atomically smooth GaAs surface is
critical to achieving high-quality Bi2Se3 films despite the relatively weak
film/substrate interaction. Calculations indicate that the Bi2Se3/GaAs
interface is likely selenium-terminated and shows no evidence of chemical
bonding between the Bi2Se3 and the substrate. These results are a guide for
integrating van der Waals materials with conventional semiconductor substrates
and serve as the first steps toward achieving an on-chip THz integrated system.