| AVS 64th International Symposium & Exhibition | |
| 2D Materials Focus Topic | Wednesday Sessions |
| Session 2D+EM+MN+NS-WeA |
| Session: | 2D Device Physics and Applications |
| Presenter: | Paul Penner, Bielefeld University, Germany |
| Authors: | P. Penner, Bielefeld University, Germany E. Marschewski, Bielefeld University, Germany X. Zhang, Bielefeld University, Germany T. Weimann, Physikalisch-Technische Bundesanstalt, Germany P. Hinze, Physikalisch-Technische Bundesanstalt, Germany A. Beyer, Bielefeld University, Germany A. Gölzhäuser, Bielefeld University, Germany |
| Correspondent: | Click to Email |
Carbon nanomembranes (CNMs) are two-dimensional materials made by cross-linking self-assembled monolayers (SAMs) of aromatic molecules via low energy electron irradiation. Previous study of molecular junction incorporating SAMs and CNMs of oligophenyl thiols has been carried out by using conical eutectic Gallium-Indium (EGaIn) top-electrodes1 and conductive probe atomic force microscopy (CP-AFM). Here we investigate the dielectric properties of pristine SAMs and CNMs with an EGaIn top electrode by impedance spectroscopy. Analysis and comparison of the tunneling resistance and capacitance density of pristine and cross-linked SAMs revealed a thickness dependent capacitance associated with the monolayer as well as a thickness independent capacitance. We adopted an equivalent circuit to take into account the contribution of the interfacial capacitance as well as the oxide layer of the EGaIn top electrode. The obtained tunneling decay constant remains unaffected after electron irradiation, which exhibits a value of about 0.5 Å-1 for both systems. A determination of dielectric constants of SAMs and CNMs from the impedance spectra will also be analyzed and discussed. Furthermore we characterize stacks of CNMs sandwiched with graphene and other 2D materials.
1 P. Penner, X. Zhang, E. Marschewski, et. al, J Phys Chem C 2014, 118, 21687.