采用HRTEM对石墨烯材料单层厚度测量的研究

将石墨烯材料薄膜制成可以通过高分辨透射电子显微镜(HRTEM) 观察的横截面样,在室温20 ℃,变换放大倍数,通过HRTEM自带的测量软件得到的单次测量值为0.411 nm,同时可以看到石墨烯材料形貌较清晰,其剖面结构并不是理想的笔直直线。通过局部剪切图和增大间隙图,提取石墨烯材料单层的边缘数据。通过直方图法获得其单层厚度的测量值,厚度均值为0.390 nm,厚度重复性测量不确定度为0.042 nm。在置信水平为95%的条件下,计算得到石墨烯材料的单层厚度为(0.390±0.086) nm。相对石墨烯厚度的公称值,石墨烯材料的单层厚度偏大,分析认为石墨烯材料层与层之间紧密连接度不够,造成单层厚度与石墨烯厚度存在差异。

The Measurement of Single-layer Thickness of Graphene Materials byHigh Resolution Transmission Electron Microscopy

The cross-sectional sample is made with the film of graphene material and is observed by high-resolution transmission electron microscopy (HRTEM).When the temperature is 20 ℃ , the value of the thickness of single-layer of graphene material measured by the software of HRTEM is 0.411 nm, otherwise, the cross-sectional of each layer of graphene material is not straight.The data of the edge of each layers could be obtained by the method of local shearing and increasing the gap, the value of thickness of the layer is 0.390 nm which is calculated by the histogram method, and the value of the uncertainty of the thickness is 0.042 nm.When the confidence level is 95%, the value of the thickness of single-layer graphene material is (0.390±0.086) nm.Compared with the nominal thickness of graphene,the calculated value of the thickness of single-layer graphene material is bigger.The difference of the thickness values is reasonable because there are gaps between the layers of grapheme material.