Reduction of graphene oxide foils by IR laser irradiation in air

Abstract

A: Graphene oxide (GO) micrometric foils have been prepared using a graphene oxide solution. A pulsed IR laser at 970 nm wavelength, with a 100 ms pulse duration and an energy between 50 mJ and 0.7 J, has been employed to irradiate the micrometric GO foils in air. Pulsed IR laser irradiation of GO foils promotes the GO reduction in air and, when the GO foils are tightened between two transparent and thin flat glasses, it permits to realize electrically conductive strips, labelled as rGO. Measurements of laser ablation yield in air as a function of the pulse energy, analysis of elemental composition of the samples before and after the irradiation and morphological characterization have been performed. An estimation of both the temperature induced by the laser treatment and the penetration depth is presented. The so-obtained rGO foils can find many interesting applications in microelectronics, engineering and bio-medicine as sensors, detectors, ion strippers and dosimeters. K: Interaction of radiation with matter; Lasers; Plasma generation (laser-produced, RF, x ray-produced); Radiation damage evaluation methods 1Corresponding author.

Graphene oxide modifications induced by excimer laser irradiations

“…36 In the case of visible and infrared (IR) laser irradiation, instead, photothermal processes are induced with GO thermal desorption of water, oxygen, and other gases and thermal ablation of carbon and other molecular species. [33][34][35]37 The Raman spectroscopy of the pristine and irradiated GO at different laser pulse energies both in air and in vacuum was performed in the shift region of about 400-3500 cm À1 . The typical vibrational modes are evident in all the μRaman spectra acquired on different UV laser pulse energy irradiating GO samples between 900 and 2000 cm À1 (D and G peaks) and between 2400 and 3400 cm À1 (2D, D + G and C peaks).…”

“…The IR laser irradiation of GO in air, using diode laser operating at 970-nm wavelength and 100-ms pulse duration, shows higher ablation yields evaluated of the order of 3.5-35 μg/pulse depending on the chosen laser pulse energy. 34 At the actual stage, it was not possible to separate the ablation yield contribution of water and carbon from the GO sample in air and in vacuum. It should be used a mass spectrometer for the in-vacuum irradiation, for instance, in order to separate the two contributions.…”

“…The IR radiation, instead, is a photothermal process producing material removing due to the high thermal process and involving a mass up to a depth due to the thermal diffusion length of the heat in the material. The IR laser irradiation of GO in air, using diode laser operating at 970‐nm wavelength and 100‐ms pulse duration, shows higher ablation yields evaluated of the order of 3.5–35 μg/pulse depending on the chosen laser pulse energy 34 …”

“…The laser absorption can be based on single and two photon absorption mechanisms, thus, photon energies of about 5 eV (248 nm) and 10 eV (double frequency) released to the GO sample may produce chemical rupture of the bonds CC (3.6 eV), CH (4.2 eV), CO (3.7 eV), C═C (6.4 eV), CC (8.7 eV), OH (4.4 eV), and others 36 . In the case of visible and infrared (IR) laser irradiation, instead, photothermal processes are induced with GO thermal desorption of water, oxygen, and other gases and thermal ablation of carbon and other molecular species 33–35,37 …”

Laser‐Assisted Rapid Fabrication of Large‐Scale Graphene Oxide Transparent Conductors

“…[ 23 ] Several studies demonstrated fabrication of conductive rGO using various types of laser. [ 24,25 ] A review of this methods can be found in ref. [ 26 ] .…”