# Nanopore Size-Dependent Raman Spectroscopy of Two-Dimensional γ‑Graphyne

## TL;DR

This paper studies how the size of nanopores in γ-graphyne affects its Raman spectroscopy, offering tools to identify and design these materials for nanodevices.

## Contribution

The paper introduces general formulas and simulations to identify N-type γ-graphynes using Raman spectroscopy.

## Key findings

- The wavenumber of Raman modes like G, G′, Y, and Y′ varies with the number of acetylene units (N).
- Formulas link lattice parameters, nanopore size, and Raman-active vibrations to N.
- Results enable fast identification of γ-graphyne types for nanodevice design.

## Abstract

Graphynes are allotropes
of carbon that display both sp and sp
2 carbons, which form
acetylene-
and benzene-like units, respectively, connected in a single-atomic
layer structure. The sp–sp
2 networks
display rich structural patterns, with different physical and chemical
properties, promising for clean energy generation and storage, optoelectronics,
heat dissipation, and molecular filter applications. Here, we apply
density-functional theory calculations to simulate the structure and
Raman spectrum of γ-graphyne monolayers with one to six acetylene
units between its carbon rings. Ready-to-use general formulas relating
the lattice parameter, nanopore size, and number of Raman-active lattice
vibrations to N are given. The wavenumber dependence
of the G, G′, Y, and Y′ modes on N reveals
differences of the order of tens of cm–1. These
results provide tools for fast and reliable identification of the N-type γ-graphynes, which is key for the architecture
design of molecular filters and other nanodevices.