Tuning the reduction and conductivity of solution-processed graphene oxide by intense pulsed light

• Published in: Carbon (New York) Vol. 102; pp. 236 - 244
• Main Authors: Al-Hamry, A., Kang, H., Sowade, E., Dzhagan, V., Rodriguez, R.D., Müller, C., Zahn, D.R.T., Baumann, R.R., Kanoun, O.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2016
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2016.02.045

We report about the reduction of spin-coated graphene oxide (GO) layers by intense pulsed light (IPL) treatment. The reduction is achieved in a few seconds resulting in semi-transparent graphene thin films with electrical conductivities up to 6.6 S/cm. In comparison to GO reduction by conventional thermal annealing in an oven, the IPL method is much faster, enabling applications in transparent and flexible polymer substrates. Moreover, this process is roll-to-roll compatible and chemicals-free. The parameters of IPL were optimized in order to tune the conductivity of reduced GO (rGO) films as a function of exposure energy, pulse duration, and number of pulses. The effect of IPL parameters on the morphology and the electrical properties of rGO films were investigated by vis-NIR, X-ray photoelectron, and Raman spectroscopies, as well as scanning electron microscopy, atomic force microscopy, and sheet resistance measurements. The correlation between Raman spectroscopy analysis and sheet resistance shows that the G band width can be used to evaluate the conductivity of the rGO. The IPL, in a time frame of seconds, results in higher conductivity than oven annealing of 30 min at 400 °C, which is also evidenced in the Raman spectra showing the same structural changes as X-ray photoelectron spectroscopy.