title: Toward the synthesis of wafer-scale single-crystal graphene on copper foils.
abstract: In this research, we constructed a controlled chamber pressure CVD (CP-CVD) system to manipulate graphene's domain sizes and shapes. Using this system, we synthesized large (~4.5 mm(2)) single-crystal hexagonal monolayer graphene domains on commercial polycrystalline Cu foils (99.8% purity), indicating its potential feasibility on a large scale at low cost. The as-synthesized graphene had a mobility of positive charge carriers of ~11,000 cm(2) V(-1) s(-1) on a SiO(2)/Si substrate at room temperature, suggesting its comparable quality to that of exfoliated graphene. The growth mechanism of Cu-based graphene was explored by studying the influence of varied growth parameters on graphene domain sizes. Cu pretreatments, electrochemical polishing, and high-pressure annealing are shown to be critical for suppressing graphene nucleation site density. A pressure of 108 Torr was the optimal chamber pressure for the synthesis of large single-crystal monolayer graphene. The synthesis of one graphene seed was achieved on centimeter-sized Cu foils by optimizing the flow rate ratio of H(2)/CH(4). This work should provide clear guidelines for the large-scale synthesis of wafer-scale single-crystal graphene, which is essential for the optimized graphene device fabrication.
authors.affiliation: Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas 77005, USA.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Yan
authors.forename: Jian
authors.initials: J
authors.lastname: Lin
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Peng
authors.forename: Zhengzong
authors.initials: Z
authors.lastname: Sun
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhu
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.forename: Changsheng
authors.initials: C
authors.lastname: Xiang
authors.forename: E Loïc
authors.initials: EL
authors.lastname: Samuel
authors.forename: Carter
authors.initials: C
authors.lastname: Kittrell
authors.forename: James M
authors.initials: JM
authors.lastname: Tour
mesh_terms: D000327:Adsorption; D003300:Copper / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D006108:Graphite / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D011312:Pressure; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D006108:Graphite; D003300:Copper