MMaterialsgateNEWS 2014/09/08

Related MaterialsgateCARDS

Atomically thin material opens door for integrated nanophotonic circuits

A new combination of materials can efficiently guide electricity and light along the same tiny wire, a finding that could be a step towards building computer chips capable of transporting digital information at the speed of light.

Reporting today in The Optical Society's (OSA) high-impact journal Optica, optical and material scientists at the University of Rochester and Swiss Federal Institute of Technology in Zurich describe a basic model circuit consisting of a silver nanowire and a single-layer flake of molybdenum disulfide (MoS2).

Using a laser to excite electromagnetic waves called plasmons at the surface of the wire, the researchers found that the MoS2 flake at the far end of the wire generated strong light emission. Going in the other direction, as the excited electrons relaxed, they were collected by the wire and converted back into plasmons, which emitted light of the same wavelength.

"We have found that there is pronounced nanoscale light-matter interaction between plasmons and atomically thin material that can be exploited for nanophotonic integrated circuits," said Nick Vamivakas, assistant professor of quantum optics and quantum physics at the University of Rochester and senior author of the paper.

Typically about a third of the remaining energy would be lost for every few microns (millionths of a meter) the plasmons traveled along the wire, explained Kenneth Goodfellow, a graduate student at Rochester's Institute of Optics and lead author of the Optica paper.

"It was surprising to see that enough energy was left after the round-trip," said Goodfellow.

Photonic devices can be much faster than electronic ones, but they are bulkier because devices that focus light cannot be miniaturized nearly as well as electronic circuits, said Goodfellow. The new results hold promise for guiding the transmission of light, and maintaining the intensity of the signal, in very small dimensions.

Ever since the discovery of graphene, a single layer of carbon that can be extracted from graphite with adhesive tape, scientists have been rapidly exploring the world of two-dimensional materials. These materials have unique properties not seen in their bulk form.

Like graphene, MoS2 is made up of layers that are weakly bonded to each other, so they can be easily separated. In bulk MoS2, electrons and photons interact as they would in traditional semiconductors like silicon and gallium arsenide. As MoS2 is reduced to thinner and thinner layers, the transfer of energy between electrons and photons becomes more efficient.

The key to MoS2's desirable photonic properties is in the structure of its energy band gap. As the material's layer count decreases, it transitions from an indirect to direct band gap, which allows electrons to easily move between energy bands by releasing photons. Graphene is inefficient at light emission because it has no band gap.

Combining electronics and photonics on the same integrated circuits could drastically improve the performance and efficiency of mobile technology. The researchers say the next step is to demonstrate their primitive circuit with light emitting diodes.

Source: University of Rochester - 04.09.2014.ph

Publication:

K. Goodfellow, R. Beams, C. Chakraborty, L. Novotny, A.N. Vamivakas "Integrated nanophotonics based on nanowire plasmons and atomically-thin material" Optica Vol. 1, Issue 3, pp.149-152 (2014).

Investigated and edited by:

Dr.-Ing. Christoph Konetschny, Inhaber und Gründer von Materialsgate
Büro für Material- und Technologieberatung
The investigation and editing of this document was performed with best care and attention.
For the accuracy, validity, availability and applicability of the given information, we take no liability.
Please discuss the suitability concerning your specific application with the experts of the named company or organization.

You want additional material or technology investigations concerning this subject?

Materialsgate is leading in material consulting and material investigation.
Feel free to use our established consulting services

MMore on this topic

When it comes to electronics, silicon will now have to share the spotlight. In a paper recently published in Nature Communications, researchers from the USC Viterbi School of Engineering describe how they have overcome a major issue in carbon nanotube technology by developing a flexible, energy-efficient hybrid circuit combining carbon nanotube thin film transistors with other thin film transistors.

This hybrid could take the place of silicon as the traditional transistor material used in electronic chips, since carbon nanotubes are more transparent, flexible, and can be processed at a lower cost. Electrical engineering professor Dr. Chongwu Zhou and USC Viterbi graduate students Haitian Chen, Yu Cao, and Jialu Zhang developed this energy-efficient circuit by integrating carbon nanotube (CNT) thin film transistors (TFT) with thin film transistors comprised of indium, gallium and zinc oxide (IGZO). “I came up with this concept in January 2013,” said Dr. Chongwu Zhou, professor in USC Viterbi’s Ming Hsieh Department of Electrical Engineering. “Before then, we were working hard... more read more

Engineers invent a process to 'dope' carbon filaments with an additive to improve their electronic performance, paving the way for digital devices that bend.

Engineers would love to create flexible electronic devices, such as e-readers that could be folded to fit into a pocket. One approach they are trying involves designing circuits based on electronic fibers, known as carbon nanotubes (CNTs), instead of rigid silicon chips. But reliability is essential. Most silicon chips are based on a type of circuit design that allows them to function flawlessly even when the device experiences power fluctuations. However, it is much more challenging to do so with CNT circuits. Now a team at Stanford has developed a process to create flexible chips that can tolerate power fluctuations in much the same way as silicon circuitry. "This is the first... more read more

UC Santa Barbara researchers demonstrate seamless designing of an atomically-thin circuit with transistors and interconnects etched on a monolayer of graphene

Researchers in electrical and computer engineering at UC Santa Barbara have introduced and modeled an integrated circuit design scheme in which transistors and interconnects are monolithically patterned seamlessly on a sheet of graphene, a 2-dimensional plane of carbon atoms. The demonstration offers possibilities for ultra energy-efficient, flexible, and transparent electronics. Bulk materials commonly used to make CMOS transitors and interconnects pose fundamental challenges in continuous shrinking of their feature-sizes and suffer from increasing "contact resistance" between them, both of which lead to degrading performance and rising energy consumption. Graphene-based transistors... more read more

A team led by Professor Keon Jae Lee from the Department of Materials Science and Engineering at KAIST has developed in vivo silicon-based flexible large scale integrated circuits (LSI) for bio-medical wireless communication.

Silicon-based semiconductors have played significant roles in signal processing, nerve stimulation, memory storage, and wireless communication in implantable electronics. However, the rigid and bulky LSI chips have limited uses in in vivo devices due to incongruent contact with the curvilinear surfaces of human organs. Especially, artificial retinas recently approved by the Food and Drug Administration (refer to the press release of FDA's artificial retina approval) require extremely flexible and slim LSI to incorporate it within the cramped area of the human eye. Although several research teams have fabricated flexible integrated circuits (ICs, tens of interconnected transistors) on... more read more

MaterialsgateNEWSLETTER

Partner of the Week

Search in MaterialsgateNEWS

Books and products

MaterialsgateFAIR:
LET YOURSELF BE INSPIRED