Researchers from ICFO, MIT and UC Riverside have been able to develop a graphene-based photodetector capable of converting absorbed light into an electrical voltage at ultrafast timescales
The efficient conversion of light into electricity plays a crucial role in many technologies, ranging from cameras to solar cells.
It also forms an essential step in data communication applications, since it allows for information carried by light to be converted into electrical information that can be processed in electrical circuits.
Graphene is an excellent material for ultrafast conversion of light to electrical signals, but so far it was not known how fast graphene responds to ultrashort flashes of light.
ICFO researchers Klaas-Jan Tielrooij, Lukasz Piatkowski, Mathieu Massicotte and Achim Woessner led by ICFO Prof. Frank Koppens and ICREA Prof. at ICFO Niek van Hulst, in collaboration with scientists from the research group led by Pablo Jarillo-Herrero at MIT and the research group led by Jeanie Lau at UC Riverside, have now demonstrated that a graphene-based photodetector converts absorbed light into an electrical voltage at an extremely high speed.
The study, entitled "Generation of photovoltage in graphene on a femtosecond timescale through efficient carrier heating", has recently been published in Nature Nanotechnology.
The new device that the researchers developed is capable of converting light into electricity in less than 50 femtoseconds (a twentieth of a millionth of a millionth of a second). To do this, the researchers used a combination of ultrafast pulse-shaped laser excitation and highly sensitive electrical readout.
As Klaas-Jan Tielrooij comments, "the experiment uniquely combined the ultrafast pulse shaping expertise obtained from single molecule ultrafast photonics with the expertise in graphene electronics. Facilitated by graphene's nonlinear photo-thermoelectric response, these elements enabled the observation of femtosecond photodetection response times."
The ultrafast creation of a photovoltage in graphene is possible due to the extremely fast and efficient interaction between all conduction band carriers in graphene. This interaction leads to a rapid creation of an electron distribution with an elevated electron temperature.
Thus, the energy absorbed from light is efficiently and rapidly converted into electron heat. Next, the electron heat is converted into a voltage at the interface of two graphene regions with different doping. This photo-thermoelectric effect turns out to occur almost instantaneously, thus enabling the ultrafast conversion of absorbed light into electrical signals. As Prof. van Hulst states, "it is amazing how graphene allows direct non-linear detecting of ultrafast femtosecond (fs) pulses".
The results obtained from the findings of this work, which has been partially funded by the EC Graphene Flagship, open a new pathway towards ultra-fast optoelectronic conversion. As Prof. Koppens comments, "Graphene photodetectors keep showing fascinating performances addressing a wide range of applications".
Generation of photovoltage in graphene on a femtosecond timescale through efficient carrier heating, Nature Nanotechnology.
K. J. Tielrooij, L. Piatkowski, M. Massicotte, A. Woessner, Q. Ma, Y. Lee, K.S. Myhro, C.N. Lau, P. Jarillo Herrero, N. van Hulst and F. H. L. Koppens.
This work was funded by the E.C. under Graphene Flagship, as well as an NWO Rubicon fellowship, an ICFO-Cofund fellowship, The Fundacio Cellex Barcelona, the ERC and the MIT MISTI-Spain program.
ICFO-The Institute of Photonic Sciences was created in 2002 by the government of Catalonia and the Technical University of Catalonia as a centre of research excellence devoted to the science and technologies of light with a triple mission: to conduct frontier research, train the next generation of scientists, and provide knowledge and technology transfer. Today, it is one of the top research centres worldwide in its category as measured by international rankings.
Research at ICFO targets the forefront of science and technology based on light with programs directed at applications in Health, Renewable Energies, Information Technologies, Security and Industrial processes, among others. The institute hosts 300 professionals based in a dedicated building situated in the Mediterranean Technology Park in the metropolitan area of Barcelona.
ICFO participates in a large number of projects and international networks of excellence and is host to the NEST program which is financed by Fundación Privada Cellex Barcelona. Ground-breaking research in graphene is being carried out at ICFO and through key collaborative research partnerships such as the FET Graphene Flagship. Prof Frank Koppens is the co-leader of the Optoelectronics work package within the Flagship program.
Alina Hirschmann | EurekAlert!
Further reports about: > Flagship > ICFO > MIT > Mediterranean > Nanotechnology > Nature Nanotechnology > Photonic > electrical circuits > electrical signals > electrical voltage > electricity > graphene > graphene electronics > heat > heating > metropolitan area > range of applications > signals > single molecule > solar cells > technologies > technology transfer > voltage
Magnetic nano-imaging on a table top
20.04.2018 | Georg-August-Universität Göttingen
New record on squeezing light to one atom: Atomic Lego guides light below one nanometer
20.04.2018 | ICFO-The Institute of Photonic Sciences
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
20.04.2018 | Physics and Astronomy
20.04.2018 | Interdisciplinary Research
20.04.2018 | Physics and Astronomy