Graphene transistors work for terahertz LED and laser devices
What is it about?
A transistor made with an atomically-thin monolayer sheet of graphene driven by dry-cell battery enables light-emission like light-emitting diodes (LEDs) as well as lasers in an unexplored terahertz frequency region. Researchers theoretically discovered in 2007, first, and now demonstrated real device operation after a decade.
Why is it important?
Quantum cascade laser is the only one operating in the terahertz frequency range as an integrated solid-state coherent light-source chip driven by dry-cell battery, but suffers from phonon decoherency preventing from room temperature operation. The novel material of graphene and its extraordinary optoelectronic properties can break through such a substantial limitation in existing technology. The key is the suppression of Auger processes, a killer for gain, by current-injection pumping that can effectively prevent from carrier heating. This paper demonstrates the feasibility and the potentiality of graphene as a terahertz integrated solid-state light-source device at 100K. The authors also address the ways towards room-temperature intense lasing operation.
The following have contributed to this page: Taiichi Otsuji