Self heating and nonlinear current-voltage characteristics in bilayer graphene

TL;DR

This paper investigates how Joule heating causes superlinear current-voltage behavior in bilayer graphene, with experiments and simulations showing it is more pronounced than in monolayer graphene due to higher density of states.

Contribution

It provides experimental and numerical evidence that Joule heating induces superlinearity in bilayer graphene's I-V characteristics, highlighting differences from monolayer graphene.

Findings

Superlinear I-V characteristics observed at low temperatures in bilayer graphene.

Superlinearity is weakly dependent on doping and sample length.

Joule heating explains the superlinearity, more significant in bilayer than monolayer graphene.

Abstract

We demonstrate by experiments and numerical simulations that the low-temperature current-voltage characteristics in diffusive bilayer graphene (BLG) exhibit a strong superlinearity at finite bias voltages. The superlinearity is weakly dependent on doping and on the length of the graphene sample. This effect can be understood as a result of Joule heating. It is stronger in BLG than in monolayer graphene (MLG), since the conductivity of BLG is more sensitive to temperature due to the higher density of electronic states at the Dirac point.