Nanomanufacturing — Key controlling properties — Part 6-11: Graphene — Defect density: Raman spectroscopy

This part of IEC TS 62607 establishes a standardized method for determining key control characteristics. — Defect density nD The graphene film grown by chemical vapor deposition and the exfoliated graphene flake are as follows. — Raman spectroscopy The defect density nD is derived from the intensity ratio of the D-peak and G-peak I(D)/I(G) in the Raman spectrum based on the three-stage model for amorphization. — This classification helps manufacturers classify material qualities and provides customers with expectations for the electronic performance of classified graphene, and more specifically, determines whether a graphene material quality is potentially suitable for various applications. It helps. — The defect density nD determined according to this document is listed as a key control characteristic in the blank detailed specification for graphene IEC 62565-3-1. The inter-defect distance LD can be calculated from the defect density nD and is an equivalent measure of defects in the graphene lattice. — The method is applicable to exfoliated graphene and graphene grown on or transferred to a substrate with I(D)/I(G) in the range of 0,1 to 3, which involves three steps of amorphization. This corresponds to a defect density of 2,39 × 10 cm-1 for the corresponding excitation energy of 2,41 eV (514 nm). — The spatial resolution is on the order of 1 μm, given by the spot size of the excited laser. — This method is complementary to the method described in IEC 62607-6-6 and determines that the Raman spectrum has a visible D-peak with an intensity ratio I(D)/I(G) in the range from 0,1 to about 3. It is used when indicating.