1. Magnetic Dipole Resonance and Coupling Effects Directly Enhance the Raman Signals of As-Grown Graphene on Copper Foil by over One Hundredfold
- Author
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Tzu-Yao Lin, Yi-Chuan Tseng, Hsuen-Li Chen, Yang-Chun Lee, Che-Kuei Ku, and Chun-Wei Chen
- Subjects
Electromagnetic field ,Materials science ,General Chemical Engineering ,Oxide ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,law.invention ,chemistry.chemical_compound ,symbols.namesake ,law ,Electric field ,Materials Chemistry ,FOIL method ,Graphene ,business.industry ,Resonance ,General Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,symbols ,Optoelectronics ,0210 nano-technology ,business ,Raman spectroscopy ,Magnetic dipole - Abstract
Large-area graphene is commonly prepared through chemical vapor deposition (CVD); in situ and nondestructive methods for its characterization are desirable. In this paper, we demonstrate a practical method—exploiting magnetic dipole resonance and coupling effects—with which the Raman signals of graphene on copper (Cu) foil can be directly, faithfully, and greatly enhanced. The magnetic dipole resonance of a silicon nanoparticle (SiNP) can effectively couple its electromagnetic field with the Cu foil to induce an enormous electric field located solely at the position of the SiNP on the graphene. The coupled electromagnetic field can lead to hot spots of high electric field intensity (E2/E02 = 123.2) within the graphene. Even when we positioned only a few SiNPs upon the graphene/Cu foil, we obtained a Raman signal enhancement (ca. 206 times) much greater than that of graphene transferred onto a 300 nm oxide film (ca. 12 times). From a series of experiments comparing the Raman signals of graphene before and ...
- Published
- 2018
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