Carbon transistors could outperform the fastest chip materials according to researchers at the University of Maryland. Graphene monolayers, sheets of pure carbon just one atom thick appears to be unfazed by temperature, unlike most semiconductors.Since the lattice vibrations were so weak in the graphene itself, a secondary, little-studied effect seemed to dominate.The phonons in the substrate, which was silicon dioxide, appeared to scatter electrons in the graphene, which is believed to limit its electron mobilities to about 40,000 cm2/Vs. Pure graphene transistors appear able to achieve their maximum possible speed at room temperature, according to the researchers, if chip makers choose the right substrate.