Obtenção de filmes de multicamadas de grafeno utilizando Dip-Coating.

Abstract

In the present work, thin films of multilayer graphene have been obtained by dip-coating, using an equipment built in our own laboratory. The films were characterized by optical microscopy, UV-vis spectroscopy, atomic force microscopy (AFM) and electrical measurement of two-point technique and by the Van der Pauw method. Three dispersions of 0.002g of graphene diluted in 10 ml of isopropanol have been prepared and each one has undergone a different time of ultrasound exposure, namely 30, 60 and 90 minutes. Each dispersion has been used for the making of 6 films with different numbers of immersion, specifically 10, 15, 20, 25, 30 and 35 immersions. The results have shown the relation between the thickness of the film and the number of immersions and the resulting decrease in transmittance as immersions increase. Regarding the ultrasound exposure, longer treatments have resulted in more uniform films formed by thinner flakes composed of fewer graphene layers. The electrical measurements of the films have revealed an electrical resistance at a rate of 103 for the 35-deposition film and 90 minutes at a rate of 102 Ω for the most deposited films and a 10² Ohms/square sheet resistance. Lastly, the present work demonstrates an alternative low-cost method with few laboratorial procedures for the attainment of conductive films of multilayer graphene in a reproducible fashion, which can be largely applied to the electronic and LCD, LED and plasma screen industries.