Observation of D band splitting in vertically aligned graphene nanowalls and their evolution with laser power during Raman spectroscopy

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology Vol. 23; no. 1
• Main Authors: Kar, Rajib, Maiti, Namita
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 2021; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Evolution; Graphene; Immunoglobulins; Inorganic Chemistry; Lasers; Materials Science; Nanoparticles; Nanotechnology; Optical Devices; Optics; Photonics; Physical Chemistry; Raman spectroscopy; Research Paper; Spectroscopy; Spectrum analysis; Splitting; Graphene nanowalls; PECVD; Raman spectroscopy; Laser measurements
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-021-05147-y

Splitting of D band is observed in vertically aligned graphene nanowalls (VAGNWs) during analysis of Raman spectroscopy for the first time and two distinct peaks were observed, designated as D
1
and D
2
. Evolution of D band with increasing laser power is studied and it is seen that intensity and full width at half maxima (FWHM) of D
2
get reduced with increasing laser power.
I
D
/
I
G
values of deposited VAGNWs showed a decreasing trend with increasing laser power indicating that defects have slightly reduced with increasing laser power. It is also observed that D
/
peak at high laser power almost merged with G peak like highly defective graphene sheets. Defect analysis showed that all the samples have high degree of stage 2 defect. Interestingly, no splitting was observed in G
/
band by increasing laser power and VAGNWs kept their turbostratic nature intact through this peak.
Graphical abstract