In-situ examination of the selective etching of an alkanethiol monolayer covered Au{111} surface

O'Dwyer, Colm

In-situ examination of the selective etching of an alkanethiol monolayer covered Au{111} surface

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Accepted Version

Date

2006-12-29

Authors

O'Dwyer, Colm

Publisher

Elsevier

Published Version

1016/j.matlet.2006.12.043

Abstract

An examination of the selective etching mechanism of a 1-alkanethiol self-assembled monolayer (SAM) covered Au{111} surface using in-situ atomic force microscopy (AFM) and molecular resolution scanning tunnelling microscopy (STM) is presented. The monolayer self-assembles on a smooth Au{111} surface and typically contains nanoscale non-uniformities such as pinholes, domain boundaries and monatomic depressions. During etching in a ferri/ferrocyanide water-based etchant, selective and preferential etching occurs at SAM covered Au(111) terrace and step edges where a lower SAM packing density is observed, resulting in triangular islands being relieved. The triangular islands are commensurate with the Au(111) lattice with their long edges parallel to its [11-0] direction. Thus, SAM etching is selective and preferential attack is localized to defects and step edges at sites of high molecular density contrast.

Keywords

Atomic force microscopy , Crystal lattices , Domain walls , Electrochemical etching , Molecular interactions , Self assembled monolayers

Citation

O'Dwyer, C. (2007) 'In-situ examination of the selective etching of an alkanethiol monolayer covered Au{111} surface'. Materials Letters, 61(18), pp. 3837-3841. doi: 1016/j.matlet.2006.12.043