Understanding and controlling the disorder in materials, especially the disorder caused by structural composition and doping effects, are important keys to studying the optical characteristics of materials. In this study, a SiO₂–Ag–reduced graphene oxide (rGO) composite structure was prepared by a simple wet chemical method, in which Ag nanoparticles (NPs) and SiO₂ were decorated onto the surface of rGO. The introduction of Si atoms can control not only the plasmon effect of Ag NPs but also, more importantly, the defect concentration of rGO. The formation of defects causes the rGO structure to enter a metastable state, which facilitates charge separation and transfer in the system. It is worth noting that changes in defect concentration can affect the energy band position of rGO; therefore, controlling the defect concentration can be used to achieve charge transfer resonance coupling. This study not only revealed the ultrahigh surface-enhanced Raman scattering activity of the substrate structure but also elucidated in detail the effect of the crystallinity of this rGO-based composite system on its optical properties.

中文翻译：

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SiO ₂ -Ag还原氧化石墨烯系统中SERS的光诱导电荷转移增强

理解和控制材料的无序性，特别是由结构组成和掺杂效应引起的无序性，是研究材料光学特性的重要关键。在这项研究中，通过简单的湿化学方法制备了SiO ₂ -Ag还原的氧化石墨烯（rGO）复合结构，其中Ag纳米颗粒（NPs）和SiO ₂被装饰在rGO的表面上。引入Si原子不仅可以控制Ag NPs的等离激元效应，而且更重要的是可以控制rGO的缺陷浓度。缺陷的形成导致rGO结构进入亚稳态，这有助于电荷在系统中的分离和转移。值得注意的是，缺陷浓度的变化会影响rGO的能带位置。因此，控制缺陷浓度可用于实现电荷转移共振耦合。这项研究不仅揭示了基材结构的超高表面增强拉曼散射活性，而且还详细阐明了该基于rGO的复合系统的结晶度对其光学性能的影响。