Adsorption structures of phenol on the Si(001)-(2 \times 1) surface calculated using density functional theory

TL;DR

This study uses density functional theory to analyze various phenol adsorption structures on Si(001)-(2x1), finding dissociated forms energetically favorable and identifying the dissociation process through simulated spectra and transition barriers.

Contribution

It provides a comprehensive DFT analysis of phenol adsorption structures on silicon, including energetic, spectral, and kinetic insights, which were not previously detailed.

Findings

Dissociated structures are energetically more favorable.

Simulated spectra match experimental data for dissociated forms.

Hydrogen atom dissociation occurs upon adsorption.

Abstract

Several dissociated and two non-dissociated adsorption structures of the phenol molecule on the Si(001)-(2 \times 1) surface are studied using density functional theory with various exchange and correlation functionals. The relaxed structures and adsorption energies are obtained and it is found that the dissociated structures are energetically more favourable than the non-dissociated structures. However, the ground state energies alone do not determine which structure is obtained experimentally. To elucidate the situation core level shift spectra for Si 2p and C 1s states are simulated and compared with experimentally measured spectra. Several transition barriers were calculated in order to determine which adsorption structures are kinetically accessible. Based on these results we conclude that the molecule undergoes the dissociation of two hydrogen atoms on adsorption.