Formation of InAs/GaAs quantum dots from a subcritical InAs wetting layer: A reflection high-energy electron diffraction and theoretical study
- Nanotechnology Research Center, Fujitsu Lab. Ltd., Morinosato-Wakamiya 10-1, Atsugi, Kanagawa 243-0197 (Japan)
InAs/GaAs quantum dots (QD's) are formed by postgrowth annealing of an InAs wetting layer thinner than the critical thickness for the transition from two- (2D) to three-dimensional (3D) growth mode. Reflection high energy electron diffraction is used to monitor the QD formation. Based on a mean-field theory [Phys. Rev. Lett. 79, 897 (1997)], the time evolution of total QD's volume, first increasing and finally saturating, is well explained by precursors forming during wetting layer growth and converting into nucleated QD's after growth stop. Both the saturation QD's volume and the QD nucleation rate depend exponentially on the InAs coverage. These behaviors and their temperature and InAs growth rate dependences are essentially understandable in the frame of the mean-field theory. Similar analysis to conventional QD growth suggests that the often observed significant mass transport from wetting layer to QD's can be ascribed to the precursors existing before 2D-3D growth mode transition.
- OSTI ID:
- 20788008
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 73, Issue 11; Other Information: DOI: 10.1103/PhysRevB.73.115327; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effects of annealing on self-assembled InAs quantum dots and wetting layer in GaAs matrix
InAs wetting layer and quantum dots on GaAs(001) surface studied by in situ STM placed inside MBE growth chamber and kMC simulations based on first-principles calculations