Kesaria, Manoj and Kumar, Mahesh and -, Govind and Shivaprasad , S. M. (2009) Effect of Pb adatom flux rate on adlayer coverage for Stranski–Krastanov growth mode on Si(1 1 1)7 × 7 surface. Applied Surface Science, 256 (2). pp. 576-579. ISSN 0169-4332

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Lead (Pb) has been a prototypical system to study diffusion and reconstruction of silicon surfaces. However, there is a discrepancy in literature regarding the critical coverage at which island formation takes place in the Stranski–Krastanov (S–K) mode. We address this issue by studying the initial stages of evolution of the Pb/Si(1 1 1)7 × 7 system by careful experiments in ultra-high vacuum with in situ characterization by auger electron spectroscopy, electron energy loss spectroscopy and low-energy electron diffraction. We have adsorbed Pb onto clean Si(1 1 1 )7 × 7 surface with sub-monolayer control at different flux rates of 0.05 ML/min, 0.14 ML/min and 0.22 ML/min, at room temperature. The results clearly show that the coverage of the Pb adlayer before the onset of 3D Pb islands in the S–K mode depends on the flux rates. LEED results show the persistence of the (7 × 7) substrate reconstruction until the onset of the island formation, while EELS results do not show any intermixing at the interface. This suggests that the flux rates influence the kinetics of growth and the passivation of dangling bonds to result in the observed rate-dependent adlayer coverages.

Item Type: Article
Additional Information: Copyright for this article belongs to M/s Elsevier B.V.
Uncontrolled Keywords: Epitaxial; (S–K) growth modes; Layer dependent mobilities; Diffusion; Auger electron spectroscopy; Electron energy loss spectroscopy; Low-energy electron diffraction; Superconductivity
Subjects: Chemistry
Materials Science
Depositing User: Ms Neetu Chandra
Date Deposited: 23 Aug 2012 11:46
Last Modified: 23 Aug 2012 11:46

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