AVS 66th International Symposium & Exhibition
    Applied Surface Science Division Thursday Sessions
       Session AS-ThP

Paper AS-ThP8
Determination of the Number of Layers of a 2D Material by Angle-Resolved Photoelectron Spectroscopy

Thursday, October 24, 2019, 6:30 pm, Room Union Station B

Session: Applied Surface Science Poster Session
Presenter: Carl A. Ventrice, Jr., SUNY Polytechnic Institute
Authors: P. Tyagi, University at Albany - SUNY
C.A. Ventrice, Jr., SUNY Polytechnic Institute
Correspondent: Click to Email
The electronic structure of most 2D materials depends on the number of molecular layers and the stacking sequence between the layers. Therefore, it is important to have a non-destructive technique for analyzing the overlayer coverage of a 2D material directly on the growth substrate. A technique for determining the number of molecular layers using angle-resolved XPS has been developed. The system that will be presented is graphene growth on CuNi substrates, where controlled growth of multilayer graphene films can be performed. Since single atomic layer graphene films can be grown on Cu substrates, these samples are used as a standard reference for a monolayer of graphene. HOPG is used as a standard reference for bulk graphite. The electron mean free path of the C-1s photoelectron can be determined by analyzing the areas under the C-1s peaks of monolayer graphene/Cu and bulk graphite. With the electron mean free path, the graphene coverage of a film of arbitrary thickness can be determined by analyzing the area under the C-1s of that sample. In principle, this technique can be used to determine the thickness of other 2D materials if a sample with a single molecular layer can be prepared.