Chemical composition of two-photon oxidized graphene

Abstract

Chemical composition of two-photon oxidized single-layer graphene is studied by micrometer X-ray photoelectron spectroscopy (XPS). Oxidized areas with a size of 2 x 2 µm 2 are patterned on graphene by tightly focused femtosecond pulsed irradiation under air atmosphere. The degree of oxidation is controlled by varying the irradiation time. The samples are characterized by four wave mixing (FWM) imaging and Raman spectroscopy/imaging. Micrometer-XPS is used to study local chemical composition of

Shaping graphene with optical forging: from a single blister to complex 3D structures

“…6 It was used in microcutting, 7,8 in ablation of graphene, [9][10][11][12][13] and in producing micro and nano-disks. 14 Direct laser writing was also applied for graphene oxide reduction, 15 for oxidation of graphene in controlled manner, 16,17 and patterning of p-n junction in graphene. 18 Recently, we demonstrated that optical forging, a direct laser writing method with tightly focused femtosecond laser beam under inert gas atmosphere, can be used for 3D shaping of graphene.…”

Revealing lattice disorder, oxygen incorporation and pore formation in laser induced two-photon oxidized graphene

“…Therefore, many methods have already been used to modify graphene, including different strategies for tailoring its shape [5][6][7][8], defect control [9][10][11], chemical modification [12][13][14][15], besides many others. Recently, an all-optical method, namely, two-photon oxidation of graphene was demonstrated, which proved to have some advantages as compared to other oxidation methods, including direct writing of device features with sub-micrometer resolution, high speed and controlled level of oxidation [16][17][18][19]. Previous atomic force microscopy (AFM), Raman and X-ray photoelectron spectroscopy (XPS) studies showed a two-photon oxidation process starting with point-like functionalized sites evolving into oxidized islands and then forming a uniform graphene oxide (GO) material mainly composed of hydroxyl (OH) and epoxide (C−O−C) functional groups with a few per cent of carboxylic (COOH) groups [17,18].…”

Optical Forging of Graphene into Three-Dimensional Shapes

“…For comparison, irradiation of the same sample with analogous patterns under air reveals characteristic signals of oxidized carbon (Supporting Information, Figure S3). 14,18,19 To further investigate the nature of the elevated plateaus we prepared a series of square patterns and compared them to square patterns made under air. In Figure 2a, two rows of squares patterned on graphene are presented.…”