Abstract:
Control of the number of graphene layers is one of the important indicators for achieving high-quality development of graphene materials. Accurate measurement of the number of layers is critical for the research, development, and application of graphene, as it significantly impacts their properties and applications. This paper first discusses the necessity of measuring the number of graphene layers and then summarizes several existing measurement methods, including the optical contrast method, Raman spectroscopy, atomic force microscopy (AFM), and high-resolution transmission electron microscopy (HRTEM). In this study, the number of layers of graphene samples prepared by mechanical exfoliation was measured and analyzed using Raman spectroscopy. Randomly selected graphene samples were tested using Raman spectroscopy. By optimizing the testing conditions, the Raman mode peak signal value for the blank silicon substrate was increased to over 5000. Using this testing method, the characteristic peaks of silicon Raman modes containing graphene samples were measured, and the ratio of Raman peak heights between graphene-containing samples and blank substrates was calculated. By comparing this ratio with the theoretical values specified in the national standard for Raman spectroscopy measurements, the number of layers of the graphene samples was determined. The test results demonstrate that the developed technique can effectively measure the number of layers in graphene film samples prepared by mechanical exfoliation, providing a reference for the study and analysis of graphene layer numbers in graphene materials.