Researchers at the University of Manchester have tested the room-temperature conductivity of atom-thick sheets of carbon nanosheets and say this material may allow a new generation of superfast microelectronics:
The team calculated that pure graphene should allow electrons to travel more easily than in any other material, including gold, silicon, gallium arsenide, and carbon nanotubes.
The mobility of charge in a semiconductor is known as its "electronic quality" and governs the speeds the material is able to provide in electronics.
For example, gallium arsenide is used in cellphone transmitters because its higher electronic quality means it can operate at greater frequencies than the silicon used for most other applications.
At room temperature, gallium arsenide has an electronic quality of 8500 cm2/Vs compared with just 1500 cm2/Vs for silicon. But good quality graphene without impurities should reach up to 200,000 cm2/Vs, according to the new research.
In experiments, the team showed that two different factors were slowing down the movement of charge.
The first factor is a "built-in" speed limit that cannot be changed: ripples in the sheets trap vibrations from heat passing through the graphene, which in turn slow down the travelling electrons.
The second source of electron congestion is impurities in the graphene. These could be removed, however, via better manufacturing, meaning the material's electronic quality should reach the proposed record-breaking levels.