纳米制造 关键控制特性 第6-12部分：石墨烯 层数：拉曼光谱、光学反射

[中文适用范围]： 本部分 IEC TS 62607 建立了一种标准化方法，用于通过拉曼光谱和光学反射确定石墨烯薄膜的关键控制特性——层数。确定层数的标准是 G 峰积分强度和光学对比度。这两种方法可以区分石墨烯和多层石墨烯，但单独使用或组合使用都无法在所有情况下（特别是所有可能的堆叠角度）确定层数。然而，通过比较两种方法得出的值，可以判断所确定的层数是否正确并可指定。 - 该方法适用于剥离的石墨烯以及生长在或转移到基底上的石墨烯，缺陷密度低，表面污染少（如转移残留物），层数不超过 5 层。 - 该方法适用于以下基底： a) 玻璃（钠钙玻璃或类似物，折射率在 532 nm 处为 1.45 至 1.55）； b) 氧化硅（硅上的 SiO2，SiO2 厚度为 90 nm ± 5 nm）。 注：90 nm 和 300 nm 是最常用的石墨烯基底 SiO2 厚度。由于当前技术水平，该方法可安全用于 90 nm ± 5 nm 厚的 SiO2 层和 532 nm 激光波长，但不适用于 300 nm ± 15 nm 的 SiO2 层，即使改变激光波长也无法满足。未来版本的 IEC TS 62607-6-12 可能包括更厚的层和其他基底。 - 空间分辨率约为 1 µm，由激发激光的斑点大小决定。 [外文原描述]： IEC TS 62607-6-12:2024 establishes a standardized method to determine the key control characteristic - number of layers for films consisting of graphene by - Raman spectroscopy and - optical reflection. Criteria for the determination of the number of layers are the G-peak integrated intensity and the optical contrast. Both methods enable to distinguish between graphene and multilayer graphene. However, neither method on its own nor the combination of the two enable a determination of the number of layers in all possible cases (especially regarding all possible stacking angles). But the comparison of the values deduced by each method allows to discriminate whether the determined number of layers is correct and can be specified or not. - The method is applicable to exfoliated graphene and graphene grown on or transferred to a substrate with a small defect density, low surface contamination (e.g. transfer residue) and number of layers up to 5. - The method is suitable for the following substrates: a) glass (soda lime glass or similar with a refractive index between 1,45 and 1,55 at 532 nm); b) oxidized silicon (SiO2 on silicon, with a SiO2 thickness of 90 nm ± 5 nm). - The spatial resolution is in the order of 1 µm given by the spot size of the exciting laser.