基于蓝宝石基底转移石墨烯的中波红外透过光谱分析

摘要

A large area of monolayer graphene was prepared by the method of ambient pressure chemical vapor deposition(CVD). In order to characterize the transmission spectroscopy of graphene in MWIR, we transferred one or three layers graphene on sapphire, which has a high transmittance at this region. Using confocal Raman spectroscopy to measure multi points on sample surface, we obtained the situation of transferred graphene layers, defects and continuity. The effect of Pauli blocking and free carrier absorption was taken into account, by which we calculated the wavelength dependence curve of optical conductivity. The transmittance of graphene samples in MWIR(3~5m)was tested by Fourier transform infrared spectroscopy. The results indicated that the transmittance of monolayer graphene is 98.5% much higher than which in visible region. The experimental data of tri-layer graphene is consistent with the simulation. Therefore, graphene is expected to make up for the deficiency of ITO as transparent electromagnetic shielding material in MWIR.%利用常压化学气相沉积（CVD）法制备大面积单层石墨烯，并分别转移一层和三层至蓝宝石基底表面。采用共焦拉曼光谱仪对样片表面多点进行测量，以表征不同位置转移石墨烯的层数、缺陷与连续性。考虑石墨烯在红外波段的自由载流子吸收和泡利阻塞效应，计算得到光电导率随波长变化的曲线。利用傅里叶变换红外光谱仪对石墨烯样品中波红外（3～5m）透过率进行了测试，结果表明其在中波红外存在明显的泡利阻塞效应。实测的单层石墨烯中波红外相对透过率为98.5%，明显高于可见区域。三层石墨烯的相对透过率也与仿真结果相仿。由此可见，石墨烯将有望弥补ITO在中波红外透明窗口电磁屏蔽应用方面的不足。