Scalable and ultrafast epitaxial growth of single-crystal graphene wafers for electrically tunable liquid-crystal microlens arrays

• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2019,（10）
• 页码范围: 659-668
• 页数: 10页
• 语种: 英文

摘要

The scalable growth of wafer-sized single-crystal graphene in an energy-efficient manner and compatible with wafer process is critical for the killer applications of graphene in high-performance electronics and optoelectronics.Here,ultrafast epitaxial growth of single-crystal graphene wafers is realized on singlecrystal Cu9oNi10(1 1 1) thin films fabricated by a tailored two-step magnetron sputtering and recrystallization process.The minor nickel (Ni) content greatly enhances the catalytic activity of Cu,rendering the growth ofa 4 in.single-crystal monolayer graphene wafer in 10 min on Cu9oNi10(1 1 1),50 folds faster than graphene growth on Cu(1 1 1).Through the carbon isotope labeling experiments,graphene growth on Cu9oNi10(1 1 1) is proved to be exclusively surface-reaction dominated,which is ascribed to the Cu surface enrichment in the CuNi alloy,as indicated by element in-depth profile.One of the best benefits of our protocol is the compatibility with wafer process and excellent scalability.A pilot-scale chemical vapor deposition (CVD) system is designed and built for the mass production of single-crystal graphene wafers,with productivity of 25 pieces in one process cycle.Furthermore,we demonstrate the application of single-crystal graphene in electrically controlled liquid-crystal microlens arrays (LCMLA),which exhibit highly tunable focal lengths near 2 mm under small driving voltages.By integration of the graphene based LCMLA and a CMOS sensor,a prototype camera is proposed that is available for simultaneous lightfield and light intensity imaging,The single-crystal graphene wafers could hold great promising for highperformance electronics and optoelectronics that are compatible with wafer process.