abstract
This study demonstrated an in situ method for quantitative characterization of nanoscale electrostatic properties of as-grown multilayer-graphene (MLG) sheets on nickel by a combination of atomic force microscopy (AFM) and Kelvin probe force microscopy (KPFM). Large area epitaxial MLG sheet were grown on nickel by Hot Filament-Thermal chemical vapor deposition (CVD) technique. The high crystalline MLG sheets on nickel were confirmed by Raman spectroscopy that revealed average G-bandwidths in the range of similar to 20 cm(-1). Herein, for the first time, the charge injection as well as subsequent charge diffusion over time on the MLG/nickel surface was demonstrated. The results unveiled that: (i) MLG surface can be either positively or negatively charged through injection process using Pt coated Si-based AFM probes; (ii) the charges accumulated and eventually reached to saturated concentrations of +4.45 (+/- 0.1) mu C/m(2) and -1.3 (+/- 0.1) mu C/m(2), respectively; (iii) the charge diffusion coefficients on graphene surface were measured to be 1.50 (+/- 0.05) + 10(-16) m(2)/s and 0.64 (+0.05) + 10-16 m(2)/s for the positive and the negative charges, respectively. The discovery of charge injection in MLG may pave the way for designing a new class of energy harvesting devices. Additionally, our study demonstrated a technique for nano-patterning/charge lithography of surface charges by contact electrification, which could be a promising application to create charged nanostructures for next generation graphene based nanoelectronic devices. (C) 2017 Elsevier Ltd. All rights reserved.
keywords
WORK-FUNCTION; OXIDE; TRANSISTORS; TRANSPORT; SHEETS; FILMS
subject category
Materials Science
authors
Bdikin, I; Sharma, DK; Otero-Lrurueta, G; Hortiguela, MJ; Tyagi, PK; Neto, V; Singh, MK
our authors
Dhananjay K. Sharma
Post-Doc Fellowshipacknowledgements
MKS and PICT would like to thanks Bilateral Cooperacao Cientifica e Tecnologica FCT/INDIA-2015/2017; between University of Aveiro, Portugal and Delhi Technological University, India (INT/PORTUGAL/P-13/2013); PTDC/CTM-NAN/121108/2010. GO-I thanks to Portuguese Foundation for Science and Technology (FCT) for a Post-Doctoral research grant (SFRH/BPD/90562/2012) and FCT-IF program. TEMA/DEM researchers also acknowledge FCT grant UID/EMS/00481/2013. IB thanks to Russian Science Foundation (Grant 16-19-10112).