Structural Modification of Single-Layer Graphene Under Laser Irradiation Featured by Micro-Raman Spectroscopy

Autor: Yurii Stubrov, Andrii Nikolenko, Viktor Strelchuk, Sergii Nedilko, Vitalii Chornii
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Nanoscale Research Letters, Vol 12, Iss 1, Pp 1-6 (2017)
Druh dokumentu: article
ISSN: 1931-7573
1556-276X
DOI: 10.1186/s11671-017-2089-6
Popis: Abstract Confocal micro-Raman spectroscopy is used as a sensitive tool to study the nature of laser-induced defects in single-layer graphene. Appearance and drastic intensity increase of D- and D′ modes in the Raman spectra at high power of laser irradiation is related to generation of structural defects. Time- and power-dependent evolution of Raman spectra is studied. The dependence of relative intensity of defective D- and D′ bands is analyzed to relate the certain types of structural defects. The surface density of structural defects is estimated from the intensity ratio of D- and G bands using the D-band activation model. Unusual broadening of the D band and splitting of the G band into G− and G+ components with redistribution of their intensities is observed at high laser power and exposition. Position of the G+ band is discussed in relation with nonuniform doping of graphene with charge impurities. Simultaneous presence in the Raman spectra of heavily irradiated graphene of rather narrow G band and broaden D band is explained by coexistence within the Raman probe of more and less damaged graphene areas. This assumption is additionally confirmed by confocal Raman mapping of the heavily irradiated area.
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