Band Gaps and Optical Spectra from Single- and Double-Layer Fluorographene to Graphite Fluoride: Many-Body Effects and Excitonic States

TL;DR

This study uses advanced many-body computational methods to analyze the electronic and optical properties of fluorographene layers and graphite fluoride, emphasizing the importance of excitonic effects in optical spectra.

Contribution

It provides a comparative first-principles analysis of band gaps and optical spectra across different fluorographene layers using GW and BSE methods, highlighting excitonic effects.

Findings

First exciton peak position is identical across single-, double-, and multilayer fluorographene.

Electron-hole interactions are essential for accurate low-energy optical spectra.

The onset of absorption spectra does not vary with layer number.

Abstract

We compare first-principle band gaps and optical absorption spectra of single- and double-layer fluorographene with bulk graphite fluoride. The electronic properties are calculated using the many-body GW approximation and the optical spectra using the Bethe-Salpeter equation (BSE). The inclusion of electron-hole interactions is crucial for predicting low energy excitonic absorption peaks. The position of the first exciton peak is identical in single-, double- and multilayer fluorographene, which may indicate that the onset of the absorption spectra does not differ in these materials.