Please use this identifier to cite or link to this item:
http://hdl.handle.net/10397/2516
Title: | Layer-by-layer nucleation mechanism for quantum dot formation in strained heteroepitaxy | Authors: | Xiang, R Lung, MT Lam, CH |
Issue Date: | 2-Aug-2010 | Source: | Physical review. E, Statistical, nonlinear, and soft matter physics, 2 Aug. 2010, v. 82, no. 2, 021601, p.1-8 | Abstract: | We study the spontaneous formation of quantum dots in the form of three-dimensional (3D) islands on facetted surfaces in heteroepitaxy. Island development from fast kinetic Monte Carlo (KMC) simulations at low deposition rates is found to follow a layer-by-layer nucleation pathway characterized by energetics driven continuous lateral expansion interrupted by a sequence of independent two-dimensional (2D) upper-layer nucleation events. The process involves only unstable 2D upper-layer nuclei but no unstable 3D nucleus. We have calculated analytically the elastic strain energy of an island in the form of an axisymmetric stepped mound using a small-slope approximation. The total free energy of a system with a 3D island and an adatom bath is obtained. Our theory explains island formation via a free energy driven layer-by-layer nucleation mechanism. Upper-layer nucleation energy barrier, nucleation time, critical radius, and island step spacings are estimated. The relevance of entropic step-step repulsion is discussed. Our theory satisfactorily explains the 3D KMC simulations and may describe the initial evolution of islands in the form of stepped mounds observed in experiments. | Keywords: | Axisymmetric Critical radius Elastic strain energy Facetted surfaces Fast kinetics Heteroepitaxy Island formation Lateral expansion Layer-by-layers Nucleation energy Nucleation mechanism Quantum Dot Spontaneous formation Three-dimensional (3D) islands Total free energy |
Publisher: | American Physical Society | Journal: | Physical review. E, Statistical, nonlinear, and soft matter physics | ISSN: | 1539-3755 | EISSN: | 1550-2376 | DOI: | 10.1103/PhysRevE.82.021601 | Rights: | © 2010 The American Physical Society. The Journal's web site is located at http://pre.aps.org/ |
Appears in Collections: | Journal/Magazine Article |
Show full item record
Page views
191
Last Week
2
2
Last month
Citations as of Apr 21, 2024
Downloads
179
Citations as of Apr 21, 2024
SCOPUSTM
Citations
16
Last Week
0
0
Last month
0
0
Citations as of Apr 19, 2024
WEB OF SCIENCETM
Citations
13
Last Week
0
0
Last month
0
0
Citations as of Apr 18, 2024
Google ScholarTM
Check
Altmetric
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.