Ermakov Victor A, Alaferdov Andrei V, Vaz Alfredo R, Perim Eric, Autreto Pedro A S, Paupitz Ricardo, Galvao Douglas S, Moshkalev Stanislav A
Center for Semiconductor Components, State University of Campinas, CP 6101, Campinas, SP, 13083-870, Brazil.
Instituto de Física "Gleb Wataghin", Universidade Estadual de Campinas, 13083-970, Campinas, SP, Brazil.
Sci Rep. 2015 Jun 23;5:11546. doi: 10.1038/srep11546.
Graphene, in single layer or multi-layer forms, holds great promise for future electronics and high-temperature applications. Resistance to oxidation, an important property for high-temperature applications, has not yet been extensively investigated. Controlled thinning of multi-layer graphene (MLG), e.g., by plasma or laser processing is another challenge, since the existing methods produce non-uniform thinning or introduce undesirable defects in the basal plane. We report here that heating to extremely high temperatures (exceeding 2000 K) and controllable layer-by-layer burning (thinning) can be achieved by low-power laser processing of suspended high-quality MLG in air in "cold-wall" reactor configuration. In contrast, localized laser heating of supported samples results in non-uniform graphene burning at much higher rates. Fully atomistic molecular dynamics simulations were also performed to reveal details of oxidation mechanisms leading to uniform layer-by-layer graphene gasification. The extraordinary resistance of MLG to oxidation paves the way to novel high-temperature applications as continuum light source or scaffolding material.
单层或多层形式的石墨烯在未来电子学和高温应用方面具有巨大潜力。抗氧化性作为高温应用的一项重要特性,尚未得到广泛研究。多层石墨烯(MLG)的可控减薄,例如通过等离子体或激光处理,是另一项挑战,因为现有方法会产生不均匀减薄或在基面引入不良缺陷。我们在此报告,通过在“冷壁”反应器配置中对空气中悬浮的高质量MLG进行低功率激光处理,可以实现加热到极高温度(超过2000 K)以及可控的逐层燃烧(减薄)。相比之下,对支撑样品进行局部激光加热会导致石墨烯以高得多的速率进行不均匀燃烧。还进行了全原子分子动力学模拟,以揭示导致均匀逐层石墨烯气化的氧化机制细节。MLG卓越的抗氧化性为作为连续光源或支架材料的新型高温应用铺平了道路。