[16p-P05-1~20] 12.2 評価・基礎物性

英語発表

[16p-P05-4] Influence of gas ratio and growth time on graphene synthesized on copper foil substrate by thermal CVD technique

〇(DC)Pathomporn Chaikhao¹, Baba Akira², Sukkaneste Tungasmita¹ (1.Chulalongkorn university, 2.Niigata university)

キーワード：

Graphene、Thermal CVD、Copper foil

In this work, we have investigated the growth of graphene layers on copper foil substrate by using thermal chemical vapor deposition (CVD) method, at different mixed gas compositions and growth durations. We analyzed the argon and hydrogen flow rates (900:100 to 980:20 sccm) and growth times (5 to 60 minutes). The detailed relationship between the concentration of hydrogen and its effects was determined. Raman spectroscopy showed a single layer of graphene was formed as the ratio of Ar: H₂ was 980:20 sccm and the ratio of I_2D/I_G was higher. Low hydrogen concentrations efficiently decompose methane on the copper surface, whereas high concentrations stimulate more nucleation, resulting in fewer layers or multilayer graphene overlaps on the surface [1]. Additionally, the growth duration affected both the number of graphene layers and the defect density in graphene microstructure. The optimal growth times of 10–20 minutes produced continuous high quality monolayer graphene with reduced defects, as evidenced by a lower I_D/I_G ratio. Prolonged growth (30–40 minutes) led to the formation of few-layer and multilayer graphene due to layer-by-layer nucleation. However, after 60 minutes, the graphene maintains the similar I_2D/I_G with a growth time of 40 minutes. This can be due to a lack of energy for the formation of the next layer, and another cause could be attributed to the hydrogen being utilized for etching the graphene instead of catalyzing [2]. Moreover, optical microscopy, AFM, and electrical measurements to support the synthesized graphene confirmed its structural, optical, and electronic properties.