큰 결정 크기를 가지는 단일층 그래핀 성장을 위한 구리 호일의 전해연마 공정 최적화
Optimized Electroplishing Process of Copper Foil Surface for Growth of Single Layer Graphene with Large Grain Size
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Graphene grown on copper-foil substrates by chemical vapor deposition (CVD) has been attracting interest for sensor applications due to an extraordinary high surface-to-volume ratio and capability of large-scale device fabrication. However, CVD graphene has a polycrystalline structure and a high density of grain boundaries degrading its electrical properties. Recently, processes such as elec- tropolishing for flattening copper substrate has been applied before growth in order to increase the grain size of graphene. In this study, we systemically analyzed the effects of the process condition of electropolishing copper foil on the quality of CVD graphene. Weobserved that electropolishing process can reduce surface roughness of copper foil, increase the grain size of CVD graphene, and min-imize the density of double-layered graphene regions. However, excessive process time can rather increase the copper foil surface rough-ness and degrade the quality of CVD graphene layers. This work shows that an optimized electropolishing process on copper substrates is critical to obtain high-quality and uniformity CVD graphene which is essential for practical sensor applications.
Abstract
Graphene grown on copper-foil substrates by chemical vapor deposition (CVD) has been attracting interest for sensor applications due to an extraordinary high surface-to-volume ratio and capability of large-scale device fabrication. However, CVD graphene has a polycrystalline structure and a high density of grain boundaries degrading its electrical properties. Recently, processes such as elec- tropolishing for flattening copper substrate has been applied before growth in order to increase the grain size of graphene. In this study, we systemically analyzed the effects of the process condition of electropolishing copper foil on the quality of CVD graphene. Weobserved that electropolishing process can reduce surface roughness of copper foil, increase the grain size of CVD graphene, and min-imize the density of double-layered graphene regions. However, excessive process time can rather increase the copper foil surface rough-ness and degrade the quality of CVD graphene layers. This work shows that an optimized electropolishing process on copper substrates is critical to obtain high-quality and uniformity CVD graphene which is essential for practical sensor applications.
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