Effects of Molecular Adsorption on Optical Losses of the Ag (111) Surface

TL;DR

This study uses first principles DFT to analyze how molecular adsorption affects optical losses on silver (111) surfaces, revealing significant spectral modifications due to surface states and adsorbed molecules.

Contribution

It provides a detailed theoretical investigation of the impact of water, methanol, and ethanol adsorption on the optical properties of Ag (111) surfaces using DFT and RPA methods.

Findings

Surface states significantly influence optical losses.

Molecular adsorption causes notable spectral modifications.

Results align with experimental observations.

Abstract

The first principles density functional theory (DFT) is applied to study effects of molecular adsorption on optical losses of silver (111) surface. The ground states of the systems including water, methanol, and ethanol molecules adsorbed on Ag (111) surface were obtained by the total energy minimization method within the local density approximation (LDA). Optical functions were calculated within the Random Phase Approximation (RPA) approach. Contribution of the surface states to optical losses was studied by calculations of the dielectric function of bare Ag (111) surface. Substantial modifications of the real and imaginary parts of the dielectric functions spectra in the near infrared and visible spectral regions, caused by surface states and molecular adsorption, were obtained. The results are discussed in comparison with available experimental data.