In this work, we investigated the edge doping effect to graphene plasmon resonances in graphene nanoribbons (GNRs), which is known to affect the electronic doping of GNRs but has not been systematically studied. We found the Fermi levels, which reflect that the sheet charge carrier densities, extracted from the graphene plasmon resonance frequencies, vary across GNRs of different widths on the same sample. Using Raman spectroscopy, we confirmed that the variation of the sheet charge carrier density is caused by edge doping, which has a stronger effect on narrower GNRs. To further understand the edge doping effect, electron beam irradiation (EBI) is applied to modify the charge state of the edge. Using EBI, we successfully demonstrated the tuning of the graphene plasmon resonances due to the change of the edge doping states. These findings demonstrated the importance of the edge doping effect in determination of the surface plasmon frequency in GNRs.

中文翻译：

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边缘掺杂对石墨烯纳米带中表面等离子体共振的影响

在这项工作中，我们研究了边缘掺杂对石墨烯纳米带（GNRs）中石墨烯等离子体共振的影响，已知它会影响GNRs的电子掺杂，但尚未进行系统的研究。我们发现费米能级反映了从石墨烯等离振子共振频率中提取的薄层电荷载流子密度在同一样品的不同宽度的GNR上都不同。使用拉曼光谱法，我们证实了片状电荷载流子密度的变化是由边缘掺杂引起的，这对较窄的GNR具有更强的影响。为了进一步了解边缘掺杂效应，可以应用电子束辐照（EBI）来修改边缘的电荷状态。使用EBI，我们成功地证明了由于边缘掺杂状态的变化而引起的石墨烯等离子体激元共振的调谐。