On the ageing mechanisms of graphene-on-metal electrodes

Graphene electrodes are being massively introduced in a wide range of electronic devices. On the contrary, exhaustive ageing studies, which are necessary prior to device commercialization, have never been performed before. Here we present the first complete reliability study of a carbon-based electrode, and the main ageing mechanisms are discussed by means of accelerated tests, nanoscale and device level experiments, as well as Weibull statistical analyses and tunneling current simulations. Our results indicate that the formation of an ultra-thin oxide layer on pristine graphene and tall oxide hillocks at graphene point defects are the main two ageing mechanisms, and they differently affect the electron transfer in the graphene sheets.