Impact of the method of separating graphene from the growth substrate on the quality of the 2D material obtained

Abstract

This article presents the research results on impact of the method of polycrystalline graphene layers separation from the growth substrate on the obtained carbon material quality. The studies were carried out on graphene sheets obtained by metallurgical method on a liquid metal substrate (HSMG® graphene). The graphene was separated using chemical etching method or the electrochemical delamination method, by separating by means of electrolysis. During electrolysis, hydrogen is emitted on a graphene-covered of cathode (metal growth substrate) as a result of the voltage applied. The graphene layer breaks away from metallic substrate by gas accumulation between them. The results from these separation processes were evaluated by means of different tools, such as SEM, TEM and AFM microscopy as well as Raman Spectroscopy. In summary, the majority of analyses indicate that the graphene obtained as a result of hydrogen delamination possesses higher purity, smaller size and number of defects, its surface is smooth and less developed after the transfer process to the target substrate.