Low-energy electron microscopy of graphene outside UHV: electron-induced removal of PMMA residues used for graphene transfer

0525529 - ÚPT 2021 RIV NL eng J - Journal Article
Materna-Mikmeková, Eliška - Müllerová, Ilona - Frank, Luděk - Paták, Aleš - Polčák, J. - Sluyterman, S. - Lejeune, M. - Konvalina, Ivo
Low-energy electron microscopy of graphene outside UHV: electron-induced removal of PMMA residues used for graphene transfer.
Journal of Electron Spectroscopy and Related Phenomena. Roč. 241, MAY (2020), č. článku 146873. ISSN 0368-2048. E-ISSN 1873-2526
R&D Projects: GA TA ČR(CZ) TE01020118; GA MŠMT(CZ) LO1212; GA MŠMT ED0017/01/01
EU Projects: European Commission(XE) 606988 - SIMDALEE2
Institutional support: RVO:68081731
Keywords : graphene * PMMA * slow electron treatment * XPS * Raman spectroscopy
OECD category: Electrical and electronic engineering
Impact factor: 1.957, year: 2020
Method of publishing: Open access
https://www.sciencedirect.com/science/article/pii/S0368204818302068

Two-dimensional materials, such as graphene, are usually prepared by chemical vapor deposition (CVD) on selected substrates, and their transfer is completed with a supporting layer, mostly polymethyl methacrylate (PMMA). Indeed, the PMMA has to be removed precisely to obtain the predicted superior properties of graphene after the transfer process. We demonstrate a new and effective technique to achieve a polymer-free CVD graphene by utilizing low-energy electron irradiation in a scanning low-energy electron microscope (SLEEM). The influence of electron-landing energy on cleaning efficiency and graphene quality was observed by SLEEM, Raman spectroscopy (the presence of disorder D peak) and XPS (the deconvolution of the C 1s peak). After removing the absorbed molecules and polymer residues from the graphene surface with slow electrons, the individual graphene layers can also be distinguished outside ultra-high vacuum conditions in both the reflected and transmitted modes of a scanning low-energy (transmission) electron microscope.
Permanent Link: http://hdl.handle.net/11104/0309642