Current Applied Physics, Vol.17, No.12, 1655-1661, 2017
2D printed graphene conductive layers with high carrier mobility
The comparison of different suspensions, obtained from the same material source subjected to electrochemical exfoliation and to analogous auxiliary treatments, but in different solutions, allowed choosing the most effective approach to obtaining graphene suspensions. It was found for the layers with a thickness of 10-20 nm printed from a water-based suspension that the sheet resistance was 5-10 k Omega/rectangle and the carrier mobility was equal to 30-40 cm(2)/V.s. The most important parameter determining the mobility of carriers in the films obtained from suspensions is found to be the flake thickness. The carrier mobility strongly decreased from similar to 100 to 0.05 cm(2)/V.s when the flake thickness changed from one monolayer to few monolayers (up to similar to 4-5 nm). This effect is most likely associated with the quality of the connection between the flakes. Only monolayer - bilayer flakes are capable of forming real connections in the film due to van-der-Waals forces. (C) 2017 Elsevier B.V. All rights reserved.
Keywords:Graphene suspensions;Electrochemical exfoliation;Water-based inks;Printed layer electric properties