We present results for a simulated inelastic electron-tunneling spectra (IETS) from calculations using the "gDFTB" code. The geometric and electronic structure is obtained from calculations using a local-basis density-functional scheme, and a nonequilibrium Green's function formalism is employed to deal with the transport aspects of the problem. The calculated spectrum of octanedithiol on gold(111) shows good agreement with experimental results and suggests further details in the assignment of such spectra. We show that some low-energy peaks, unassigned in the experimental spectrum, occur in a region where a number of molecular modes are predicted to be active, suggesting that these modes are the cause of the peaks rather than a matrix signal, as previously postulated. The simulations also reveal the qualitative nature of the processes dominating IETS. It is highly sensitive only to the vibrational motions that occur in the regions of the molecule where there is electron density in the low-voltage conduction channel. This result is illustrated with an examination of the predicted variation of IETS with binding site and alkane chain length.

Solomon, G., Gagliardi, A., Pecchia, A., Frauenheim, T., DI CARLO, A., Reimers, J., et al. (2006). Understanding the inelastic electron-tunneling spectra of alkanedithiols on gold. THE JOURNAL OF CHEMICAL PHYSICS, 124(9) [10.1063/1.2166362].

Understanding the inelastic electron-tunneling spectra of alkanedithiols on gold

DI CARLO, ALDO;
2006-01-01

Abstract

We present results for a simulated inelastic electron-tunneling spectra (IETS) from calculations using the "gDFTB" code. The geometric and electronic structure is obtained from calculations using a local-basis density-functional scheme, and a nonequilibrium Green's function formalism is employed to deal with the transport aspects of the problem. The calculated spectrum of octanedithiol on gold(111) shows good agreement with experimental results and suggests further details in the assignment of such spectra. We show that some low-energy peaks, unassigned in the experimental spectrum, occur in a region where a number of molecular modes are predicted to be active, suggesting that these modes are the cause of the peaks rather than a matrix signal, as previously postulated. The simulations also reveal the qualitative nature of the processes dominating IETS. It is highly sensitive only to the vibrational motions that occur in the regions of the molecule where there is electron density in the low-voltage conduction channel. This result is illustrated with an examination of the predicted variation of IETS with binding site and alkane chain length.
Pubblicato
Rilevanza internazionale
Articolo
Sì, ma tipo non specificato
Settore ING-INF/01 - Elettronica
English
Con Impact Factor ISI
alcohols; carrier concentration; electronic structure; gold; paraffins; spectrum analysis; vibrations (mechanical); density-functional scheme; highly sensitive; low-energy peaks; electron tunneling
Solomon, G., Gagliardi, A., Pecchia, A., Frauenheim, T., DI CARLO, A., Reimers, J., et al. (2006). Understanding the inelastic electron-tunneling spectra of alkanedithiols on gold. THE JOURNAL OF CHEMICAL PHYSICS, 124(9) [10.1063/1.2166362].
Solomon, G; Gagliardi, A; Pecchia, A; Frauenheim, T; DI CARLO, A; Reimers, J; Hush, N
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/40997
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