Kinetics of GaAs (001) surfaces investigated by LEEM-MBE

Gomez Sanchez, Daniel 2019. Kinetics of GaAs (001) surfaces investigated by LEEM-MBE. PhD Thesis, Cardiff University. Item availability restricted.

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Abstract

Understanding the physical mechanisms behind epitaxial growth of semiconductors is crucial for the comprehensive control of the interfaces and ultimately for the fabrication of state-of-the-art optimised optoelectronic devices i.e. single-photon emitters or quantum computing. The current in-situ characterisation techniques have certain limitations in analysing dynamic processes during growth. Our unique III-Vs LEEM-MBE system at Cardiff, allows us to resolve dynamical processes on III-Vs under MBE conditions i.e. nucleation of nanostructures, with atomic resolution in the vertical axis and 5 nm in the XY plane at video rate. We have developed a new technique: Selective Energy Dark-Field Low Energy Electron Microscopy (SEDFLEEM), which conjoins the advantages of Dark-Field LEEM with the accuracy of the I-V curve of diffracted spots for identification of complex structures generated at GaAs(001) surfaces. This technique provides a very useful tool for the investigation of atomic arrangements and nanostructures nucleation. Studies on the c(8⨯2) and the (6⨯6) phase reconstructions for GaAs(001) using SEDFLEEM revealed a metastable (6⨯6) within the stable c(8⨯2) regime that is present in the surface at temperatures above 570°C. Using the principles of droplet epitaxy, we have from used a Gallium droplet, to generate a monotonically decreasing Gallium chemical potential (µ

Item Type:	Thesis (PhD)
Date Type:	Completion
Status:	Unpublished
Schools:	Physics and Astronomy
Subjects:	Q Science > QC Physics
Uncontrolled Keywords:	Semiconductors, LEEM, MBE, GaAs, Reconstruction, Diffraction, Dark-field
Funders:	Cardiff University, School of Physics and Astronomy
Date of First Compliant Deposit:	21 August 2020
Last Modified:	25 May 2021 01:24
URI:	https://orca.cardiff.ac.uk/id/eprint/134286

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