Deep-ultraviolet Raman scattering studies of monolayer graphene thin films
Deep-ultraviolet Raman scattering studies of monolayer graphene thin films
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DOI：
10.1016/j.carbon.2014.10.028
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发表时间：
2015
期刊：
影响因子：
10.9
通讯作者：
Hsiang-Lin Liu;Syahril Siregar;E. H. Hasdeo;Y. Kumamoto;C. Shen;Chia-Chin Cheng;Lain‐Jong Li;R. Saito;S. Kawata
中科院分区：
文献类型：
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作者：
Hsiang-Lin Liu;Syahril Siregar;E. H. Hasdeo;Y. Kumamoto;C. Shen;Chia-Chin Cheng;Lain‐Jong Li;R. Saito;S. Kawata
我们目前的联合实验和理论研究单层石墨烯薄膜的深紫外拉曼散射光谱。我们发现，在266 nm激光激发下，虽然G模式仍然明显，但G ′模式未被观察到。G ′模在紫外波段表现出明显的线宽展宽。在355、532和785 nm波长处，G ′模和G模的峰值强度比显著增加。所有的实验结果与紧束缚方法计算的理论值符合得很好。从理论上证明了G '模的积分强度与入射光子能量成反比，而G模的积分强度则随着入射光子能量的四次幂而增加。这些结果扩展了我们对石墨烯远离狄拉克锥的双共振拉曼散射过程的理解，并为石墨烯在深紫外频率范围内的未来技术重要发展提供了基础。
We present joint experimental and theoretical investigations of the deep-ultraviolet Raman scattering spectra of monolayer graphene thin films. We found that upon a 266 nm laser excitation, while the G mode remains pronounced, the G′ mode is not observed. The G′ mode exhibits distinctive linewidth broadening towards the ultraviolet frequency region. The peak intensity ratio of the G′ and G modes increases dramatically excited at 355, 532, and 785 nm wavelengths. All of the experimental findings are in good agreement with the theory calculated by the tight-binding method. We theoretically show that the integrated intensity of the G′ mode is inversely proportional to the incident photon energy, whereas that of the G mode increases as the fourth power of the incident photon energy. These results extend our understanding of the double resonance Raman scattering process of graphene away from the Dirac cones and provide the foundation for future technologically important developments of graphene in the deep-ultraviolet frequency range.