Vapor Trapping Growth of Single-Crystalline Graphene Flowers: Synthesis, Morphology, and Electronic Properties

• Published in: Nano letters Vol. 12; no. 6; pp. 2810 - 2816
• Main Authors: Zhang, Yi, Zhang, Luyao, Kim, Pyojae, Ge, Mingyuan, Li, Zhen, Zhou, Chongwu
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 13.06.2012
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Crystallization - methods; Electric Conductivity; Electron states and collective excitations in thin films, multilayers, quantum wells, mesoscopic and nanoscale systems; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronics; Exact sciences and technology; Flowers; Fullerenes and related materials; diamonds, graphite; Gases - chemistry; Graphene; Graphite - chemistry; Lobes; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Macromolecular Substances - chemistry; Materials science; Materials Testing; Molecular Conformation; Morphology; Nanostructure; Nanostructures - chemistry; Nanostructures - ultrastructure; Particle Size; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Single crystals; Specific materials; Surface Properties; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Synthesis; Transistors; Trapping; Vapor trapping; large-grain graphene; morphology; graphene growth; graphene transistors; Grain size; Methane; Electronic properties; Electron backscattering; Electron diffraction; Field effect transistors; Boron nitride; Crystal growth from vapors; Monocrystals; Trapping; Hexagonal crystals; Graphene; Morphology; Growth mechanism
• DOI: 10.1021/nl300039a
• ISSN: 1530-6984; 1530-6992

We report a vapor trapping method for the growth of large-grain, single-crystalline graphene flowers with grain size up to 100 μm. Controlled growth of graphene flowers with four lobes and six lobes has been achieved by varying the growth pressure and the methane to hydrogen ratio. Surprisingly, electron backscatter diffraction study revealed that the graphene morphology had little correlation with the crystalline orientation of underlying copper substrate. Field effect transistors were fabricated based on graphene flowers and the fitted device mobility could achieve ∼4200 cm2 V–1 s–1 on Si/SiO2 and ∼20 000 cm2 V–1 s–1 on hexagonal boron nitride (h-BN). Our vapor trapping method provides a viable way for large-grain single-crystalline graphene synthesis for potential high-performance graphene-based electronics.