IBM researchers are using graphene sheets to make photo(light) detectors. Graphene transports electrons very quickly, tens of times faster than current photo detectors (made by materials called III-V semiconductors), and can also absorb more light frequencies (visible and infrared).
It is already known that when metal contacts are deposited on graphene, electric fields are generated at the interface between the two materials. So the researchers took advantage of this field. Their device is a piece of multilayered graphene with metal contacts on top. When they shine light near the contact, the field separates the electrons and holes, and a current is generated.
A single-sheet of Graphene can absorb 2.3% of the light falling on it, which is a lot for a one-atom-thick material.
An ultra-fast photodetector could be used to make next-gen optical communication networks ( with rates over 40-gigabits per second), optical computers, medical equipment, and more.