The Growth and Microstructure of GaAs Embedded with Al Nanocrystals

Abstract

The preparation and the microstructure of GaAs embedded with Al nanocrystals prepared by Laser molecular beam epitaxy were investigated. The microstructure of the sample was observed by transmission electron microscope. The reflection high-energy electron diffraction (RHEED) pattern varied from the stripe pattern to the spot pattern at the beginning of the Al nanocrystals growth, and then the spot pattern tended to change to the stripe pattern. There was a large lattice mismatch between Al and GaAs substrate, and Al formed three-dimensional islands on the GaAs substrate, which led to the RHEED transformation into the spot pattern. Otherwise, the dislocations would be formed between the GaAs layer and Al islands due to the large lattice mismatch. Meanwhile, there was some polycrystal of GaAs around the Al islands.

Keywords

GaAs thin films / epitaxial growth / laser molecular beam epitaxy / film growth mechanism

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