Nucleation and growth of graphene/Mo2C heterostructures on Cu through CVD. Issue 2 (30th October 2021)

• Record Type: Journal Article
• Authors: Turker, Furkan; Caylan, Omer R.; Buke, Goknur
• Is Part Of: Journal of the American Ceramic Society. Volume 105:Issue 2(2022)
• Page Start: 815
• Page End: 822
• Publication Date: 2021-10-30
• Subjects: activation energy -- CVD -- graphene -- Mo2C; Ceramics -- Periodicals; 620.1405
• DOI: 10.1111/jace.18187
• Languages: English
• ISSNs: 0002-7820

Abstract

Abstract: We investigated the chemical vapor deposition synthesis of Mo2 C/graphene heterostructures on a partially wetted liquid copper surface, studied the morphology of resulting phases using electron and optical microscopy, and determined the rate‐limiting step for the growth of Mo2 C on graphene. The morphology of the Mo2 C crystals varied from the center to the edge of the copper substrate because of the change in the Mo diffusion pathways owing to the variation in the thickness of the Cu substrate. Thin, hexagonal‐shaped crystals of Mo2 C were found in the central region, where Cu is the thickest. In addition, the growth pressure substantially affects the nucleation and growth kinetics of both Mo2 C and graphene. At high pressures (750 Torr), the graphene layer fully covered the Cu surface and Mo2 C crystals formed with a regular shape, while at low pressures (5 Torr), the nucleation of both domains was suppressed, leading to the evolution of Mo2 C crystals with irregular shapes. The activation energy for the growth of Mo2 C on graphene was calculated to be 3.76 ± 0.3 eV, and the diffusion of Mo to the Cu surface through uncovered Cu or graphene vacancies/defects was determined to be the rate‐limiting step.