Effect of Gas Atmosphere in the Heating Stage on Limiting Nucleation of Graphene on Copper Foils by Low Pressure Chemical Vapor Deposition. Issue 3 (3rd February 2020)

• Record Type: Journal Article
• Authors: Shi, Yonggui; Wang, Yunwei; Ren, Yang; Wan, Yuhui
• Is Part Of: Crystal research and technology. Volume 55:Issue 3(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-02-03
• Subjects: atmosphere -- copper -- graphene -- nitrogen -- nucleation; Crystallography -- Periodicals; 548
• DOI: 10.1002/crat.201900181
• Languages: English
• ISSNs: 0232-1300

Abstract

Abstract: To investigate the effect of gas atmosphere in the heating stage of graphene fabrication on graphene nucleation, hydrogen and nitrogen are introduced into the furnace respectively in the heating stage. The results show that graphene growing on copper foils heated in nitrogen atmosphere and in hydrogen atmosphere present different nucleation characteristics. The analysis implies that the gas atmosphere in the heating stage affects the graphene nucleation and growth by changing the morphology of the copper surface and the inherent carbon concentration in the substrate, and this change actually results from the interaction of the copper surface and the gas atmosphere. The difference in size and quality of the fabricated graphene domains also indicates nitrogen atmosphere in the heating stage favors fabricating large‐sized graphene domains with good quality. Thus, substituting hydrogen for nitrogen in the heating stage would be a simpler and easier way to depress graphene nucleation as well as improve the graphene quality. Abstract : The copper surface heated in hydrogen and nitrogen presents different characteristics. This difference results from the interaction of copper surface with nitrogen and hydrogen, namely hydrogen causes terraced step surface, favoring graphene nucleation while nitrogen favors the formation of smooth surface, limiting graphene nucleation. Thus, heating copper substrate in nitrogen in the heating stage can depress graphene nucleation, effectively.