Vibrational properties of graphdiynes as 2D carbon materials beyond graphene

TL;DR

This study uses density-functional theory to analyze the vibrational spectra of various graphdiyne 2D carbon materials, revealing how their structure influences vibrational modes and aiding in their characterization.

Contribution

It provides a detailed symmetry-based analysis of IR and Raman spectra for different graphdiyne topologies, enhancing understanding of their vibrational properties.

Findings

Identification of marker bands sensitive to topology

Correlation between structure and vibrational spectra

Effective vibrational spectroscopy characterization

Abstract

Two-dimensional (2D) hybrid sp-sp2 carbon systems are an appealing subject for science and technology. For these materials, topology and structure significantly affect electronic and vibrational properties. We investigate here by periodic density-functional theory (DFT) calculations we here investigate the Raman and IR spectra of 2D carbon crystals belonging to the family of graphdiynes (GDYs) and having different structures and topologies. By joining DFT calculations with symmetry analysis, we assign the IR and Raman modes in the spectra of all the investigated systems. On this basis, we discuss how the modulation of the Raman and IR active bands depends on the different interactions between sp and sp2 domains. The symmetry-based classification allows identifying the marker bands sensitive to the different peculiar topologies. These results show the effectiveness of vibrational spectroscopy for the characterization of new nanostructures, deepening the knowledge of the subtle interactions that take place in these 2D materials.