• 文献标题:   Graphene Domain Signature of Raman Spectra of sp(2) Amorphous Carbons
  • 文献类型:   Article
  • 作  者:   SHEKA EF, GOLUBEV YA, POPOVA NA
  • 作者关键词:   sp 2 amorphous carbon, amorphics with molecular structure, onephonon twophonon raman spectra, electrical anharmonicity, graphene domain
  • 出版物名称:   NANOMATERIALS
  • ISSN:  
  • 通讯作者地址:   RUDN Univ
  • 被引频次:   0
  • DOI:   10.3390/nano10102021
  • 出版年:   2020

▎ 摘  要

The standard D-G-2D pattern of Raman spectra of sp(2) amorphous carbons is considered from the viewpoint of graphene domains presenting their basic structure units (BSUs) in terms of molecular spectroscopy. The molecular approximation allows connecting the characteristic D-G doublet spectra image of one-phonon spectra with a considerable dispersion of the C=C bond lengths within graphene domains, governed by size, heteroatom necklace of BSUs as well as BSUs packing. The interpretation of 2D two-phonon spectra reveals a particular role of electrical anharmonicity in the spectra formation and attributes this effect to a high degree of the electron density delocalization in graphene domains. A size-stimulated transition from molecular to quasi-particle phonon consideration of Raman spectra was experimentally traced, which allowed evaluation of a free path of optical phonons in graphene crystal.