Abstract Large-area single-crystal graphene (LSG) over half a millimeter were synthesized via chemical vapor deposition, and a flexible ion gel-gated graphene field-effect transistor (FET) was fabricated to explore the electrical properties of the graphene based on the mechanism of electronic double layers. A procedure of cyclical oxidation/hydrogen-annealing processes by chemical vapor deposition (CVD) was proposed and optimized as a new growth method for the large single-crystal graphene, to facilitate the reconstruction of copper foil surface. To form a flexible FET on the polyethylene terephthalate substrate, LSG was utilized as a channel layer, and a spin-coated ion gel film was used as a gate dielectric. The flexible device demonstrates excellent electrical properties and high degree of bendability. When the device was bent by 8.1%, the on/off current ratio exceeded 400 because the deformation of the graphene crystal lattice widened graphene’s bandgap. This work is a fundamental study on the growth mechanism of LSG and the two-dimensional-material-based ion gel-gated transistor for application in flexible electronic devices.

中文翻译：

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基于大面积单晶石墨烯的高开关电流比柔性场效应晶体管

摘要 通过化学气相沉积法合成了超过 0.5 毫米的大面积单晶石墨烯 (LSG)，并制作了柔性离子凝胶门控石墨烯场效应晶体管 (FET)，以探索基于石墨烯的电学性质。双电子层的机理。提出并优化了化学气相沉积（CVD）循环氧化/氢退火工艺，作为大单晶石墨烯的新生长方法，以促进铜箔表面的重建。为了在聚对苯二甲酸乙二醇酯基板上形成柔性 FET，LSG 用作沟道层，旋涂的离子凝胶膜用作栅极电介质。柔性器件表现出优异的电气性能和高度的可弯曲性。当设备弯曲 8.1% 时，开/关电流比超过400，因为石墨烯晶格的变形扩大了石墨烯的带隙。这项工作是对 LSG 的生长机制和基于二维材料的离子凝胶门控晶体管在柔性电子器件中的应用的基础研究。