scope:

This part of IEC TS 62607 establishes a standardized method to determine the key control characteristic

• defect density n_D

of graphene films grown by chemical vapour deposition as well as exfoliated graphene flakes by

• Raman spectroscopy.

The defect density n_D is derived from the intensity ratio of the D-peak and the G-peak I(D)/I(G) in the Raman spectrum based on the three-stage model for amorphization.

• The classification helps manufacturers to classify their material quality and customers to provide an expectation of the electronic performance of the classified graphene and more specifically to decide whether or not the graphene material quality is potentially suitable for various applications.

• The defect density n_D determined in accordance with this document is listed as a key control characteristic in the blank detail specification for graphene IEC 62565-3-1. The inter-defect distance L_D can be calculated from the defect density n_D and is an equivalent measure of defects in the graphene lattice.

• The method is applicable for 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 corresponds to a defect density of 2,46 × 10¹⁰ cm⁻¹ up to 7,39 × 10¹¹ cm⁻² for an excitation energy of 2,41 eV (514 nm), corresponding to stage 1 of the three-stage model for amorphization.

• The spatial resolution is in the order of 1 μm given by the spot size of the exciting laser.

• The method is complementary to the method described in IEC 62607-6-6 and is used if the Raman spectrum shows a visible D-peak with an intensity ratio I(D)/I(G) in the range of 0,1 to around 3.