Stability of Surface Reconstructions on InAs(001)
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Surface reconstructions for InAs(001)
Equilibrium phase diagram for InAs(001)
Equilibrium phase diagram for InAs(001) with strain
Relevant Publications
Surface reconstructions for InAs(001)
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| We have studuied the stability of different surface reconstructions on InAs(001) with density-functional theory calculations (DFT). The most important surface reconstructions are the a2 2x4 and b2 2x4, which are schematically shown here on the right. A number of other reconstructions has been considered as well. | |
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Shown is the equlibrium phase diagram as obtained from DFT calculations for InAs(001). The b2, a2, and z reconstructions are energetically stable, for decreasing As overpressure. The stability of the b2 and a2 has also been confirmed experimentally, as can be seen in the following STM image that were obtained under As rich and poor conditions, respectively. These images were obtained by our experimental colleagues at HRL Laboratories (Bill Barvosa-Carter, James Owen, Jenna Zinck). |
STM Images confirm theoretical predictions:
For very low As overpressure, the calculations suggest that the z 4x2 structure is stable. This has not yet been confirmed experimentally. Thus, the correct 4x2 structure for InAs(001) still remains as a puzzle.
Equilibrium phase diagram for InAs(001)
with strain
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We have also calculated the stability of the surface reconstructions as a function of external strain. Shown are
the equilibrium phase diagrams for 4% compressive and 4% tensile strain in comparison to the unstrained phase diagram:
It is evident that the region of stability for all reconstructions changes as a function of strain. Thus, some
structures that are stable during homoepitaxy might become unstable upon strain. Vice versa, it is possibile that
normally unstable reconstructions may be stabilized upon external strain.
Relevant Publications
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C. Ratsch, W. Barvosa-Carter, F. Grosse, J.H.G. Owen, and J.J. Zinck, Surface Reconstructions for InAs(001) Studied with DFT and STM , Phys. Rev. B 62, R7719 (2000). PDF or Link to journal
C. Ratsch, Strain Induced Change of Surface Reconstructions for InAs(001)
, Phys. Rev. B 63, 161306(R) (2001). PDF or Link
to journal
Related pages
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High resolution kinetic Monte Carlo simulation for InAs(001)