Researchers from CNR-IFN, Politecnico di Milano, the University of Pisa, the Graphene Center of Cambridge (UK) and ICN2 of Barcelona (Spain) have shown that the relaxation time of graphene charge carriers can be significantly modified by applying an external electrical field.
Graphene is able to efficiently absorb light from the visible to the infrared through the photoexcitation of its charge carriers. After light absorption, its photoexcited charge carriers cool down to the initial equilibrium state in a few picoseconds, corresponding to a millionth of a millionth of a second. The remarkable speed of this relaxation process makes graphene particularly promising for a number of technological applications, including light detectors, sources and modulators.