Researchers at the UC Riverside Bourns College of Engineering have built and successfully tested an amplifier made from graphene that could lead to more efficient circuits in electronic chips, such as those used in Bluetooth headsets and toll collection devices in cars.
Graphene, a single-atom thick carbon crystal, was first isolated in 2004 by Andre Geim and Konstantin Novoselov, who won the Nobel Prize in physics this month for that work. Graphene has many extraordinary properties, including superior electrical and heat conductivity, mechanical strength and unique optical absorption.
The demonstration at UCR of the graphene amplifier with signal processing functions is a major step forward in graphene technology because it is a transition from individual graphene devices to graphene circuits and chips, said Alexander Balandin, a professor of electrical engineering, who performed the work along with a graduate student and researchers at Rice University.
The triple-mode amplifier based on graphene has advantages over amplifiers built from conventional semiconductors, such as silicon, said Balandin, who is also chair of the UC Riverside Materials Science and Engineering program. The graphene amplifier reveals greater functionality and a faster speed because of graphene’s electrical ambipolarity (current conduction by negative and positive charges).
It can be switched between different modes of operation by a simple change of applied voltage. These characteristics are expected to result in simpler and smaller chips, a faster system response and less power consumption.
The experimental demonstration of the graphene amplifier functionality was reported last week in the journal ACS Nano.
The fabrication and experimental testing were performed in Balandin's Nano-Device Laboratory. The co-authors of the paper are Guanxiong Liu, one of Balandin’s graduate students, Kartik Mohanram, an assistant professor at Rice University, and Xuebei Yan, one of Mohanram's graduate students.
The researchers from Rice University designed the amplifier and testing protocol. Liu built the device in the UCR clean room. Liu and Yan then tested the amplifier in Balandin’s lab.
The triple-mode amplifier can be charged at anytime during operation in the three modes: positive, negative or both. By combining these three modes, the researchers demonstrated the amplifier can achieve the modulation necessary for phase shift keying and frequency shift keying, which are widely used in wireless and audio applications.
These applications include: Bluetooth headsets for cell phones; radio frequency identification (RFID), which is used in wireless products, including toll collection devices in cars, cards used to pay for public transportation and identification tags on animals; and ZigBee, a communication protocol used in devices such as such as wireless light switches with lamps and electrical meters with in-home-display.
The University of California, Riverside (www.ucr.edu) is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment of over 19,000 is expected to grow to 21,000 students by 2020. The campus is planning a medical school and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Graduate Center. The campus has an annual statewide economic impact of more than $1 billion.
A broadcast studio with fiber cable to the AT&T Hollywood hub is available for live or taped interviews. To learn more, call (951) UCR-NEWS.
Sean Nealon | EurekAlert!
Will Earth still exist 5 billion years from now?
08.12.2016 | KU Leuven
Home computers discover a record-breaking pulsar-neutron star system
08.12.2016 | Max-Planck-Institut für Radioastronomie
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Materials Sciences
08.12.2016 | Materials Sciences
08.12.2016 | Physics and Astronomy