Adsorption of organic molecules on semiconductor surfaces has been attracting a growing attention for its importance in emerging technologies. Since the properties of the resulting materials are largely dependent on the organic/semiconductor interface, fundamental research on the covalent bonding of molecules with the surface can provide useful information. Problems that have been addressed include the structure of the resulting systems and spectroscopic measurements often in concert with theoretical calculations can assess the orientation and geometry of the molecular adsorbate. NEXAFS spectroscopy is widely used to characterize adsorbate structures on surfaces since it allows to investigate the adsorption mode as well as the extent of the adsorbate-substrate interaction, through the comparison between the spectra of the free and adsorbed molecule. Here we present a DFT simulation of the NEXAFS spectra of ethylene adsorbed on a regular Si (100) surface, considering several adsorption models. Cluster models have been employed to mimic the molecule-surface system for the spectra simulation. Surface models with and without the adsorbed molecule have been optimized by means of periodic slab DFT calculations. Angle dependent spectra have been also calculated and compared with available polarization dependent NEXAFS experiments, revealing the suitability of this technique to derive the adsorption configuration of the molecule on the surface.

C K-edge NEXAFS spectra of model systems for C2H4 on Si(100): a DFT simulation

ROMEO, MICHELE;DE FRANCESCO, RENATO;STENER, MAURO;BALDUCCI, GABRIELE;FRONZONI, GIOVANNA
2011-01-01

Abstract

Adsorption of organic molecules on semiconductor surfaces has been attracting a growing attention for its importance in emerging technologies. Since the properties of the resulting materials are largely dependent on the organic/semiconductor interface, fundamental research on the covalent bonding of molecules with the surface can provide useful information. Problems that have been addressed include the structure of the resulting systems and spectroscopic measurements often in concert with theoretical calculations can assess the orientation and geometry of the molecular adsorbate. NEXAFS spectroscopy is widely used to characterize adsorbate structures on surfaces since it allows to investigate the adsorption mode as well as the extent of the adsorbate-substrate interaction, through the comparison between the spectra of the free and adsorbed molecule. Here we present a DFT simulation of the NEXAFS spectra of ethylene adsorbed on a regular Si (100) surface, considering several adsorption models. Cluster models have been employed to mimic the molecule-surface system for the spectra simulation. Surface models with and without the adsorbed molecule have been optimized by means of periodic slab DFT calculations. Angle dependent spectra have been also calculated and compared with available polarization dependent NEXAFS experiments, revealing the suitability of this technique to derive the adsorption configuration of the molecule on the surface.
2011
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11368/2834178
 Avviso

Registrazione in corso di verifica.
La registrazione di questo prodotto non è ancora stata validata in ArTS.

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact