Research on Control Method of Graphene Layers Grown in Air Holes of Photonic Crystal Fiber Based on Raman Spectroscopy
WANG Xiao-yu1, CUI Yong-zhao1, BI Wei-hong1,2*, FU Guang-wei1, KE Si-cheng1, WANG Wen-xin1
1. College of Information Science and Engineering, Yanshan University, Qinhuangdao 066004, China
2. Key Laboratory for Special Fiber and Fiber Sensor of Hebei Province, Qinhuangdao 066004, China
Abstract：Graphene and photonic crystal fiber have good optical properties, but it is difficult to transfer/coat graphene on the inner holes with small diameter by the wet-transfer method which can be only transferring graphene on the surface or end of the PCF. Therefore, the chemical vapor deposition was used to decompose the carbon source into carbon atoms, allowing it to form nucleation points in the air holes of the optical fiber, and then by controlling the growth conditions, the graphene with different layers can be directly grown on the inner holes of the photonic crystal fiber. By scanning electron microscopy, it can be clearly noticed that the presence of graphene film which was tightly in combination with air holes of the photonic crystal fiber. In addition, all three characteristic peaks of graphene were shown by Raman spectroscopy. By changing the growth conditions such as temperature, growth time, methane gas concentration, it was found that the ratio of D peak to G peak of the graphenein the air holes of the photonic crystal fiber significantly reduced to around 0.5, which can effectively reduce the rate of the defects. The results of the Raman spectra showed that the growth time was the most effective for reducing defects in graphene. When the growth time was 5 h, bilayer graphene was achieved grown. By extending the growth time, the defects in graphene can be continuously reduced. The nucleation points of carbon atoms were influenced by temperature, which speeded up the formation of graphene film, but greater defectswere caused with excessive temperature in graphene, resulting in decreasing of the ratio of D peak to G peak after 1 050 ℃. With increasing of the methane concentration, on the other hand, affected by the diameter of the air hole, the number of graphene layers were increased in fluctuation. This research provides a basis for the subsequent design of devices based on graphene fiber and the applications in optics.
Key words：Graphene; Photonic crystal fiber; Raman spectroscopy; Chemical vapor deposition
王晓愚，崔永兆，毕卫红，付广伟，柯思成，王文馨. 基于拉曼光谱的光子晶体光纤孔内生长石墨烯层数控制方法的研究[J]. 光谱学与光谱分析, 2020, 40(12): 3659-3664.
WANG Xiao-yu, CUI Yong-zhao, BI Wei-hong, FU Guang-wei, KE Si-cheng, WANG Wen-xin. Research on Control Method of Graphene Layers Grown in Air Holes of Photonic Crystal Fiber Based on Raman Spectroscopy. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2020, 40(12): 3659-3664.
