Nanosecond laser treatment of graphene

• Published in: Applied surface science Vol. 276; pp. 133 - 137
• Main Authors: Kiisk, Valter, Kahro, Tauno, Kozlova, Jekaterina, Matisen, Leonard, Alles, Harry
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2013; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; CVD graphene; Exact sciences and technology; Laser irradiation; Photoluminescence; Physics; Raman spectroscopy; 82.80.Gk; Photoluminescence; 79.20.Eb; Laser irradiation; 81.05.ue; Raman spectroscopy; CVD graphene; CVD; Raman spectra; Laser radiation; Physical radiation effects; Film growth
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2013.03.047

•Single 5ns laser shots ablate CVD graphene with threshold fluence ~200mJ/cm2.•Damage threshold for UV irradiation depends strongly on sample.•Raman spectra indicate formation of oxidized graphene in ablated areas.•Oxidized graphene residues in ablated areas produce strong fluorescence. Laser processing of graphene is of great interest for cutting, patterning and structural engineering purposes. Tunable nanosecond lasers have the advantage of being relatively widespread (compared to e.g. femtosecond or high-power continuous wave lasers). Hereby we have conducted an investigation of the impact of nanosecond laser pulses on CVD graphene. The damage produced by sufficiently strong single shots (pulse width 5ns, wavelength 532 or 266nm) from tunable optical parametric oscillator was investigated by the methods of scanning electron microscopy and optical microspectroscopy (Raman and fluorescence). Threshold of energy density for producing visible damage was found to be ~200mJ/cm2. For UV irradiation the threshold could be notably less depending on the origin of sample. Surprisingly strong fluorescence signal was recorded from damaged areas and is attributed to the residues of oxidized graphene.