Unusually strong lateral interaction in the CO overlayer in phosphorene-based systems

TL;DR

This study combines vibrational spectroscopy and DFT calculations to reveal unusually strong lateral interactions in CO overlayers on phosphorene, showing distinct vibrational modes and stable adsorption at room temperature.

Contribution

It uncovers the strong lateral interactions affecting CO vibrational spectra on phosphorene, supported by experimental and theoretical agreement.

Findings

Stable CO adsorption on phosphorene at room temperature

Identification of two distinct C-O vibrational energies

Unusual vibrational band activated by lateral interactions

Abstract

By means of vibrational spectroscopy and density functional theory (DFT), we investigate CO adsorption on phosphorene-based systems. We find stable CO adsorption at room temperature on both phosphorene and bulk black phosphorus. The adsorption energy and vibrational spectrum have been calculated for several possible configurations of the CO overlayer. We find that the vibrational spectrum is characterized by two different C-O stretching energies. The experimental data are in good agreement with the prediction of the DFT model and unveil the unusual C-O vibrational band at 165-180 meV, activated by the lateral interactions in the CO overlayer.