Electron microscopy reveals structure and morphology of one molecule thin organic films.
Nano Lett
; 12(3): 1295-9, 2012 Mar 14.
Article
em En
| MEDLINE
| ID: mdl-22339758
ABSTRACT
Transmission electron microscopy was used to determine the structure of molecular films of self-assembled monolayers of pentathiophene derivatives supported on various electron transparent substrates. Despite the extreme beam sensitivity of the monolayers, structural crystallographic maps were obtained that revealed the nanoscale structure of the film. The image resolution is determined by the minimum beam diameter that the radiation hardness of the monolayer can support, which in our case is about 90 nm for a beam current of 5 × 10(6) e(-)/s. Electron diffraction patterns were collected while scanning a parallel electron beam over the film. These maps contain uncompromised information of the size, symmetry and orientation of the unit cell, orientation and structure of the domains, degree of crystallinity, and their variation on the micrometer scale, which are crucial to understand the electrical transport properties of the organic films. This information allowed us to track small changes in the unit cell size driven by the chemical modification of the support film.
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Base de dados:
MEDLINE
Assunto principal:
Compostos Orgânicos
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Microscopia Eletrônica
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Nanoestruturas
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Membranas Artificiais
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article