Atmospheric Pressure Cvd Graphene Prepared Process Parameters Research And Its Application In Laser Tuning Q

In this paper, the synthesis of high quality graphene film on Cu foil by atmospheric pressure chemical vapor deposition (APCVD) was studied systematically. The effect of several synthesized parameters, including the growth temperature and time, the H2/Ar environment of growth process and the treatment of Cu foil, on the structure of graphene films were investigated in detail and the optimal growth parameters were concluded. The high quality graphene films were prepared at850℃for10min with250/750sccm H2/Ar environment of growth process and300/300sccm H2/Ar environment during the treatment of Cu foil.The high quality graphene films were obtained with the optimal parameters. For further investigating the structure and the quality of the optimal graphene sample, several measurements were employed to analyze the characters of the best graphene films. The results showed that the size of the film was about10mm×10mm; the surface of graphene films were smooth, uniform and with few cracks; the transmittance of the sample was81.0%-92.7%with the wavelength range of330-900nm; the IG/I2D value of the Raman spectra of the best sample was only1.02, so the layer number of the graphene sample was estimated to be2-3, and the small value of ID/IG (0.53) showed that the defect density of the graphene sample was low as well; the layer number of the best graphene films could be calculated to be～3from the TEM images of the sample, and we also had observed the single layer graphene films from the same sample.Additionally, the sheet resistance of all the graphene films prepared by atmospheric pressure CVD was measured. It is found that the trend of the sheet resistance of all samples matched with the theoretical curve better, and the minimum sheet resistance we measured was2403.5Ω/□.The optimal prepared graphene film was inserted to the Nd:YAG laser operating at1064nm as the saturable absorber material, and the shortest pulse width of242.8ns could be obtained with the single-pulse energy of8.18μJ, and the peak power of33.69W. The results indicated that graphene films synthesized by APCVD could be used as saturable absorber materials in ultrashort pulse laser, which was meaningful and valuable in the practical applications.