New Insight into the Characterization of Graphene Oxide and Reduced Graphene Oxide Monolayer Flakes on Si-Based Substrates by Optical Microscopy and Raman Spectroscopy
New Insight into the Characterization of Graphene Oxide and Reduced Graphene Oxide Monolayer Flakes on Si-Based Substrates by Optical Microscopy and Raman Spectroscopy
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DOI：
10.1021/acs.jpcc.1c01152
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发表时间：
2021-04-02
影响因子：
3.7
通讯作者：
Yoshimura, Masamichi
中科院分区：
文献类型：
--
作者：
De Silva, K. Kanishka H.;Viswanath, Pamarti;Yoshimura, Masamichi
氧化石墨烯（GO）和还原氧化石墨烯（RGO）作为原始石墨烯的经济替代品引起了人们的兴趣，其可控性能跨越了许多领域的应用。 GO和RGO中存在大量的晶格缺陷，使其物理和化学性质与原始石墨烯有很大不同。这使得它们的识别和表征变得模糊，因为应用于原始石墨烯的规则可能不适用于 GO 和 RGO。在这里，我们通过拉曼光谱和光学可视化报告了对沉积在不同常用硅基基底上的 GO 和热还原 GO 单层薄片的表征的新见解，以解决这种不确定性。研究发现，由于多层系统界面处的多次反射和干涉，在可见光范围内具有较低反射率的介电基板在正常白光照明和强拉曼信号下具有更好的光学对比度。因此，具有 90 nm SiO2 层的 Si 基板可提供最高的 I-G'/I-G 比以及单层 RGO 薄片更好的光学可见度。
Graphene oxide (GO) and reduced GO (RGO) have attracted interest as economical alternatives for pristine graphene with controllable properties spanning their applications in many fields. Abundant lattice defects present in GO and RGO have made their physical and chemical properties largely diverse from that of pristine graphene. This makes their identification and characterization ambiguous as the rules applied for pristine graphene may not be practical for GO and RGO. Here, we report a new insight into the characterization of GO and thermally reduced GO monolayer flakes deposited on different commonly used Si-based substrates by Raman spectroscopy along with optical visualization to address this uncertainty. It was found that the dielectric substrates with a lower reflectance in the visible range give a better optical contrast under normal white light illumination and intense Raman signals owing to the multiple reflection and interference at the interfaces of the multilayer system. Accordingly, a Si substrate with a 90 nm SiO2 layer gives the highest I-G'/I-G ratio along with a better optical visibility for monolayer RGO flakes.