Raman spectrum of graphene with its versatile future perspectives

Raman spectroscopy is performing as a powerful analytical technique for qualitative and quantitative analysis of graphene and graphene-related compounds. Graphene and graphene-related compounds exhibit intense Raman vibrations. Raman spectroscopic techniques for determination of several graphene layers, and the quality and type of edges, disorders, and functional groups in graphene and graphene-related compounds are of increasing importance. Herein, we review the developments and discuss the future direction and various questions relevant to Raman spectroscopic analysis of graphene and graphene-related compounds. An update of the basic concepts underlying the Raman spectroscopy of graphene is presented and conclusions regarding this matter are provided. The biomedical and physical applications of Raman spectroscopy of graphene are evaluated. The chemical enhancement of the Raman signals and studies of these enhancements are known as Surface enhanced Raman spectroscopy (SERS) and Tip enhanced Raman spectroscopy (TERS). Different mechanisms of achieving chemical enhancement of the Raman signal of the graphene surface and study of these enhancements through Raman spectroscopy are discussed in this critical review illustrating the growth in the use of Raman spectroscopy in graphene research.