Incidence of multilayers in chemically exfoliated graphene

Autor: Szirmai, P., Márkus, B. G., Chacón-Torres, J. C., Eckerlein, P., Edelthalhammer, K., Englert, J. M., Mundloch, U., Hirsch, A., Hauke, F., Náfrádi, B., Forró, L., Kramberger, C., Pichler, T., Simon, F.
Rok vydání: 2018
Předmět:
Zdroj: Scientific Reports 9, 19480 (2019)
Druh dokumentu: Working Paper
DOI: 10.1038/s41598-019-55784-6
Popis: An efficient route to synthesize macroscopic amounts of graphene is highly desired and a bulk characterization of such samples, in terms of the number of layers, is equally important. We present a Raman spectroscopy-based method to determine the distribution of the number of graphene layers in chemically exfoliated graphene. We utilize a controlled vapor-phase potassium intercalation technique and identify a lightly doped stage, where the Raman modes of undoped and doped few-layer graphene flakes coexist. The spectra can be unambiguously distinguished from alkali doped graphite, and a modeling with the distribution of the layers yields an upper limit of flake thickness of five layers with a significant single-layer graphene content. Complementary statistical AFM measurements on individual few-layer graphene flakes find a consistent distribution of the layer numbers.
Databáze: arXiv