Researchers develop single photon LEDs
Researchers from the Graphene Flagship have used layered materials to create an all-electrical quantum light emitting diode (LED) with single-photon emission.
The researchers, from the Physics and Engineering Department of the University of Cambridge, UK, developed LEDs that have the potential as ‘on-chip’ photon sources in quantum information applications.
The ultra-thin devices are constructed of thin layers of different layered materials, stacked together to form a heterostructure. Electrical current is injected into the device, tunnelling from single-layer graphene, through few-layer boron nitride acting as a tunnel barrier, and into the mono- or bi-layer TMD material, such as tungsten diselenide (WSe2), where electrons recombine with holes to emit single photons.
Professor Mete Atatüre from Cavendish Laboratory, University of Cambridge, UK, co-author of the research, said: “Ultimately, in a scalable circuit, we need fully integrated devices that we can control by electrical impulses, instead of a laser that focuses on different segments of an integrated circuit.
“There are many emitters that are optically excitable, but only a handful are electrically driven.”
The layered nature also offers an advantage over some other single-photon emitters for feasible and effective integration into nanophotonic circuits.
Professor Frank Koppens from The Institute of Photonic Sciences (ICFO), Spain, leader of Work Package 8 – Optoelectronics and Photonics, added: “Electrically driven single photon sources are essential for many applications, and this first realisation with layered materials is a real milestone.
“This ultra-thin and flexible platform offers high levels of tunability, design freedom, and integration capabilities with nano-electronic platforms including silicon CMOS.”
Professor Andrea Ferrari, Chair of the Graphene Flagship Management Panel, and the Flagship’s Science and Technology Officer, who also co-authored the research, said: “We are just scratching the surface of the many possible applications of devices prepared by combining graphene with other insulating, semiconducting, superconducting or metallic layered materials.”
Ferrari discusses the Graphene Flagship in Horizon 2020 Projects: Portal – Issue 11, which can be accessed here.
