Congratulations to Maria!

Paper about the  study of environmental effects on the nanogap in graphene formation was just accepted for publication to Nanoscale!

  • From Electroburning to Sublimation: Substrate and Environmental Effects in the Electrical Breakdown Process of Monolayer Graphene
    Maria El Abbassi, Laszlo Posa, Peter Makk, Cornelia Nef, Kishan Thodkar, Andras Halbritter, and M. Calame.
    Nanoscale, , -, 2017. [DOI]

    We report on the characterization of the Electrical Breakdown (EB) process for the formation of tunneling nanogaps in single-layer graphene. In particular{,} we investigated the role of oxygen in the breakdown process by varying the environmental conditions (vacuum and ambient conditions). We show that the density of oxygen molecules in the chamber is a crucial parameter that defines the physical breakdown process: at low density{,} the graphene lattice is sublimating{,} whereas at high density the process involved is oxidation{,} independent on the substrate material. To estimate the activation energies of the two processes{,} we use a scheme which consists of applying voltage pulses across the junction during the breaking. By systematically varying the voltage pulse length{,} and estimating the junction temperature from a 1D thermal model{,} we extract activation energies which are consistent with the sublimation of graphene in high vacuum and the electroburning process in air. Our study indicates that a better control of the gaps formation is suitable in the sublimation regime.

New paper on nanogap formation in graphene is accepted to Nanoscale! Congratulations to Maria!