Evidence for Electron Transfer between Graphene and Non-Covalently Bound pi-Systems
Journal article, 2020
Hybridizing graphene and molecules possess a high potential for developing materials for new applications. However, new methods to characterize such hybrids must be developed. Herein, the wet-chemical non-covalent functionalization of graphene with cationic pi-systems is presented and the interaction between graphene and the molecules is characterized in detail. A series of tricationic benzimidazolium salts with various steric demand and counterions was synthesized, characterized and used for the fabrication of graphene hybrids. Subsequently, the doping effects were studied. The molecules are adsorbed onto graphene and studied by Raman spectroscopy, XPS as well as ToF-SIMS. The charged pi-systems show a p-doping effect on the underlying graphene. Consequently, the tricationic molecules are reduced through a partial electron transfer process from graphene, a process which is accompanied by the loss of counterions. DFT calculations support this hypothesis and the strong p-doping could be confirmed in fabricated monolayer graphene/hybrid FET devices. The results are the basis to develop sensor applications, which are based on analyte/molecule interactions and effects on doping.
trication
doping
functionalization
graphene
sensors
Author
Steffen Brülls
Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry
Valentina Cantatore
Chalmers, Chemistry and Chemical Engineering, Energy and Material
Zhenping Wang
Freie Universität Berlin
Eric Tam
Chalmers, Industrial and Materials Science, Materials and manufacture
Per Malmberg
Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry
Jessica Stubbe
Freie Universität Berlin
Biprajit Sarkar
Freie Universität Berlin
University of Stuttgart
Itai Panas
Chalmers, Chemistry and Chemical Engineering, Energy and Material
Jerker Mårtensson
Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry
Siegfried Eigler
Freie Universität Berlin
Chemistry - A European Journal
0947-6539 (ISSN) 1521-3765 (eISSN)
Vol. 26 29 6694-6702Subject Categories
Materials Chemistry
Theoretical Chemistry
Condensed Matter Physics
DOI
10.1002/chem.202000488
PubMed
32227533