suspended CVD graphene
Our paper entitled “Mobility Enhancement in Graphene by in situ Reduction of Random Strain Fluctuations” appeared in Phys. Rev. Lett.
Bumps on a road slow down our pace, so do corrugations in graphene to travelling electrons. By flattening the corrugations out, we help electrons move effectively faster through a graphene sheet. The sample quality of graphene has been improved significantly since its discovery. One factor that limited further improvements has not been investigated directly so far, namely corrugations in the graphene sheet, i.e. microscopic distortions that form even when placed on atomically flat surfaces. Such corrugations can scatter the electrons when moving through an electronic device. We have developed a technique to pull the graphene sheet on two opposite sides and thereby flattening and smoothing it, similar to pulling on a piece of crumpled paper which irons out wrinkles and folds. After this process, the electrons travel effectively faster through the graphene sheet, their “mobility” increases, demonstrating an improved sample quality. These findings not only help us to further understand the electron transport in graphene but also provide instructions for studying other two-dimensional materials.