Abstract We demonstrate modulated H 2 and O 2 plasma treatments as an effective methodology for controlled chemical functionalization by hydrogen and oxygen atoms of single- and multi-layer chemical vapor deposition (CVD) graphene aiming at engineering material properties. The effects of the functionalization degree on the optical and transport properties of graphene are discussed with a twofold aim of (i) providing reproducible experimental protocols for tailoring graphene properties, and of (ii) providing insights into the chemical mechanisms involved in the plasma-processing of graphene with hydrogen and oxygen atoms. An unprecedented control over the graphene functionalization by hydrogen atoms is demonstrated together with the fine tuning of multi-layer graphene resistivity as well as the transition from metallic to semiconducting behavior with a gap opening. The interaction of oxygen atoms with multilayer graphene provides a strong modification of surface wettability without significant change in conductivity, thus suggesting that oxidation effects are mainly confined on the outmost graphene. Moreover, the air exposure of graphene oxidized by plasma treatment results in peculiar chemical mechanisms with important effect on the transport properties of the material. Finally, we investigate the restoration of graphene from graphene oxide by modulated hydrogen plasma.

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通过调制等离子体处理工程石墨烯特性

摘要 我们证明了调制的 H 2 和 O 2 等离子体处理是一种有效的方法，通过氢原子和氧原子对单层和多层化学气相沉积 (CVD) 石墨烯进行控制化学功能化，以实现工程材料特性。讨论功能化程度对石墨烯光学和传输特性的影响有两个目的：(i) 提供可重复的实验方案来定制石墨烯特性，以及 (ii) 提供对等离子体处理中涉及的化学机制的见解具有氢和氧原子的石墨烯。氢原子对石墨烯官能化的前所未有的控制与多层石墨烯电阻率的微调以及从金属到半导体行为的转变与间隙开放一起被证明。氧原子与多层石墨烯的相互作用在不显着改变电导率的情况下提供了表面润湿性的强改性，因此表明氧化作用主要局限于最外面的石墨烯。此外，通过等离子体处理氧化石墨烯的空气暴露导致特殊的化学机制，对材料的传输性能有重要影响。最后，我们研究了通过调制氢等离子体从氧化石墨烯中恢复石墨烯。氧原子与多层石墨烯的相互作用在不显着改变电导率的情况下提供了表面润湿性的强改性，因此表明氧化作用主要局限于最外面的石墨烯。此外，通过等离子体处理氧化石墨烯的空气暴露导致特殊的化学机制，对材料的传输性能有重要影响。最后，我们研究了通过调制氢等离子体从氧化石墨烯中恢复石墨烯。氧原子与多层石墨烯的相互作用在不显着改变电导率的情况下提供了表面润湿性的强改性，因此表明氧化作用主要局限于最外面的石墨烯。此外，通过等离子体处理氧化石墨烯的空气暴露导致特殊的化学机制，对材料的传输性能有重要影响。最后，我们研究了通过调制氢等离子体从氧化石墨烯中恢复石墨烯。