PORTLAND, Ore. -- Pure sheets of graphene promise to run cooler yet faster than today's silicon chips.
Unfortunately defect-free graphene sheets are extremely difficult to grow and
even harder to characterize for defects
Cornell University researchers claim to have
invented an imaging technique that simplifies their metrology by coloring
graphene sheets to quickly identify their properties.
The new technique distinguishes the areas of
graphene sheets which are true monolayers by colorizing the edges of perfect
patches. Using diffraction imaging electron microscopy, the technique measures
the angles at which electrons bounce off the sheets' surface, using different
colors to identify them. The result is a colorized image of the sheets that can
quickly identify grain boundaries according to their orientation.
The resulting images look like patchwork
quilts with the large solid areas representing perfect monolayer patches, the colored edges representing imperfect boundaries betweenthe patches.
Funding for the graphene research was provided by the National Science
Foundation through the Cornell Center for Materials Research and the Nanoscale
Science and Engineering Initiative.