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|
| Type |
Poster Presentation |
| Area |
Physical Chemistry |
| Room No. |
Grand Ballroom |
| Time |
10월 19일 (금요일) 11:00~12:30 |
| Code |
PHYS.P-200 |
| Subject |
Raman Spectroscopic Study of Electronic Interactions between Graphene and Copper Substrates
|
| Authors |
Jieun Choi, Sunmin Ryu*
Department of Chemistry, Pohang University of Science and Technology, Korea
|
| Abstract |
Raman spectroscopy has been a versatile tool to characterize various material properties of graphene such as structural defects, thickness, stacking, strain and charge density. While chemical vapor deposition (CVD) of graphene on copper substrates is one of the primary preparation methods for both fundamental research and industrial application, Raman scattering of as-grown graphene/Cu system has not been studied regarding how their interactions affect the electronic structure of graphene and thus its Raman spectra. In this work, we investigated as-grown graphene on Cu foils and Cu thin film/SiO2/Si substrates using multi-wavelength Raman spectroscopy and atomic force microscopy (AFM). Excitation energy was varied in the range of 1.58 ~ 3.81 eV to minimize spectral interference of photoluminescence from Cu substrates. Most of all, both samples exhibited significant frequency deviations for G and 2D peaks with respect to those of freestanding reference samples. The smaller frequency changes observed for the latter samples were partly attributed to the less thermal expansion and compression of the substrates during the CVD growth. Secondly, 2D peak frequency of both samples were ~20 cm-1 higher than expected even when the effects of strain and charge density were considered. Based on quantification of the effects of strain and charge density, we concluded that the unknown contribution was made by reduction in the Fermi velocity of graphene that was induced by its intimate interaction with underlying Cu substrates. The quantitative analysis of the change in the electronic structure given in this study will be highly useful in characterizing as-grown graphene and possibly in other forms. |
| E-mail |
cju5598@postech.ac.kr |
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122nd General Meeting of the KCS