Ab initio optical properties of Si(100)

TL;DR

This study uses density functional theory to compute the optical properties of Si(100) surfaces, revealing how different reconstructions affect spectra and aligning with experimental data.

Contribution

It provides ab initio calculations of Si(100) surface optical properties, highlighting the influence of atomic geometry on spectra and validating results with experiments.

Findings

Reconstruction type significantly affects optical spectra.

Differential Reflectivity spectrum matches experimental positive peak.

Atomic geometries strongly influence Reflectance Anisotropy Spectra.

Abstract

We compute the linear optical properties of different reconstructions of the clean and hydrogenated Si(100) surface within DFT-LDA, using norm-conserving pseudopotentials. The equilibrium atomic geometries of the surfaces, determined from self-consistent total energy calculations within the Car-Parrinello scheme, strongly influence Reflectance Anisotropy Spectra (RAS), showing differences between the p(2x2) and c(4x2)reconstructions. The Differential Reflectivity spectrum for the c(4x2) reconstruction shows a positive peak at energies < 1 eV, in agreement with experimental results.