Mechanisms of defect generation and clustering in CH 3S Self-assembled monolayers on Au(111)

Periodic density functional calculations probe that step edges play a key role as source of defects during self-assembly. It is shown that the self-assembly process strongly reduces the energy required to strip an atom from the gold surface, locally increasing the concentration of surface defects. T...

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Detalles Bibliográficos
Autores: Carro, P., Torres, D., Diaz, R., Salvarezza, Roberto Carlos, Illas, F.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2012
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/75178
Acceso en línea:http://hdl.handle.net/11336/75178
Access Level:acceso abierto
Palabra clave:Au(111)
Thiols
Sams
Defects
https://purl.org/becyt/ford/2.10
https://purl.org/becyt/ford/2
Descripción
Sumario:Periodic density functional calculations probe that step edges play a key role as source of defects during self-assembly. It is shown that the self-assembly process strongly reduces the energy required to strip an atom from the gold surface, locally increasing the concentration of surface defects. The thermodynamic driving force for the atom stripping is considerably more favorable along step-edge lines within the self-assembly than on the higher-coordinated terrace sites. Furthermore, the clustering of surface defects is considered, and we probe that the formation of aggregates of vacancies in the form of vacancy pits significantly stabilizes the self-assembly on the terraces of gold, where the role of the step edges is expected to be less significant. The high stability of pit-like structures arises from a balance between the corrugation and the enhanced bonding of defect-rich substrates. Our results demonstrate the important role that step edges play during assembly and could be very valuable for discovering defect-free assembled structures.