Laser-induced forward transfer of carbon nanowalls for soft electrodes fabrication

Carbon nanowalls (CNW) are two-dimensional interconnected graphitic nanostructures that have a few mu m in length and height, reaching typical thicknesses of a few tens of nm. We present results on such layers synthesized in a low pressure argon plasma jet, injected with acetylene and hydrogen, on transparent substrates (quartz) heated at 600 degrees C, without catalyst. Thermogravimetric analysis reveals that the CNW are stable up to 420 degrees C in air, and Raman spectroscopy investigations highlight their graphene-like structure. Finally, using a pulsed Nd:YAG laser device (355 nm, 50 ps), we show that 2D-arrays of CNW (pixels and lines) can be printed by laser-induced forward transfer (LIFT), preserving their architecture and structure. Electrical measurements on 1 mu m thick CNW demonstrate typical values in the range of 357.5-358.4 Omega for the samples grown on Au/Cr electrodes, and in the range of 450.1-474.7 Omega for the LIFT printed lines (under positive, negative, and neutral polarization; 1 kHz-5 MHz frequency range; 500 mV and 1 V, respectively). Their morphology is highlighted by means of optical and electronic microscopy. Such structures have potential applications as soft conductive lines, in sensor development and/or embedding purposes. (C) 2015 Elsevier B.V. All rights reserved.