(Press-News.org) Faster electronic device architectures are in the offing with the unveiling of the world's first fully two-dimensional field-effect transistor (FET) by researchers with the Lawrence Berkeley National Laboratory (Berkeley Lab). Unlike conventional FETs made from silicon, these 2D FETs suffer no performance drop-off under high voltages and provide high electron mobility, even when scaled to a monolayer in thickness.
Ali Javey, a faculty scientist in Berkeley Lab's Materials Sciences Division and a UC Berkeley professor of electrical engineering and computer science, led this research in which 2D
heterostructures were fabricated from layers of a transition metal dichalcogenide, hexagonal boron nitride and graphene stacked via van der Waals interactions.
"Our work represents an important stepping stone towards the realization of a new class of electronic devices in which interfaces based on van der Waals interactions rather than covalent bonding provide an unprecedented degree of control in material engineering and device exploration," Javey says. "The results demonstrate the promise of using an all-layered material system for future electronic applications."
Javey is the corresponding author of a paper describing this research in ACS Nano titled "Field-Effect Transistors Built from All Two-Dimensional Material Components". Co-authors are Tania Roy, Mahmut Tosun, Jeong Seuk Kang, Angada Sachid, Sujay Desai, Mark Hettick and Chenming Hu.
FETs, so-called because an electrical signal sent through one electrode creates an electrical current throughout the device, are one of the pillars of the electronics industry, ubiquitous to computers, cell phones, tablets, pads and virtually every other widely used electronic device. All FETs are comprised of gate, source and drain electrodes connected by a channel through which a charge-carrier - either electrons or holes – flow. Mismatches between the crystal structure and atomic lattices of these individual components result in rough surfaces – often with dangling chemical bonds - that degrade charge-carrier mobility, especially at high electrical fields.
"In constructing our 2D FETs so that each component is made from layered materials with van der Waals interfaces, we provide a unique device structure in which the thickness of each component is well-defined without any surface roughness, not even at the atomic level," Javey says. "The van der Waals bonding of the interfaces and the use of a multi-step transfer process present a platform for making complex devices based on crystalline layers without the constraints of lattice parameters that often limit the growth and performance of conventional heterojunction materials."
Javey and his team fabricated their 2D FETs using the transition metal dichalcogenide molybdenum disulfide as the electron-carrying channel, hexagonal boron nitride as the gate insulator, and graphene as the source, drain and gate electrodes. All of these constituent materials are single crystals held together by van der Waals bonding.
For the 2D FETs produced in this study, mechanical exfoliation was used to create the layered components. In the future, Javey and his team will look into growing these heterogeneous layers directly on a substrate. They will also look to scale down the thickness of individual components to a monolayer and the lengths of the channels to molecular-scale dimensions.
INFORMATION:
This research was funded by the U.S. Department of Energy's Office of Science.
2-D transistors promise a faster electronics future
Berkeley Lab researchers create the first fully 2-D field effect transistors
2014-06-03
ELSE PRESS RELEASES FROM THIS DATE:
Investigating unusual three-ribbon solar flares with extreme high resolution
2014-06-03
The 1.6 meter telescope at Big Bear Solar Observatory (BBSO) in California has given researchers unparalleled capability for investigating phenomena such as solar flares. Operated by New Jersey Institute of Technology (NJIT), the BBSO instrument is the most powerful ground-based telescope dedicated to studying the star closest to Earth.
On June 2, Distinguished Professor of Physics Haimin Wang joined NJIT colleagues at the 224th meeting of the American Astronomical Society (AAS), held in Boston, Massachusetts, to present intriguing data about solar flares — specifically, ...
Solving sunspot mysteries
2014-06-03
Multi-wavelength observations of sunspots with the 1.6-meter telescope at Big Bear Solar Observatory (BBSO) in California and aboard NASA's IRIS spacecraft have produced new and intriguing images of high-speed plasma flows and eruptions extending from the Sun's surface to the outermost layer of the solar atmosphere, the corona. Operated by New Jersey Institute of Technology (NJIT), BBSO houses the largest ground-based telescope dedicated to solar research.
On June 2, NJIT researchers reported on the acquisition of these images at the 224th meeting of the American Astronomical ...
Complex neural circuitry keeps you from biting your tongue
2014-06-03
DURHAM, N.C. -- Eating, like breathing and sleeping, seems to be a rather basic biological task. Yet chewing requires a complex interplay between the tongue and jaw, with the tongue positioning food between the teeth and then moving out of the way every time the jaw clamps down to grind it up.
If the act weren't coordinated precisely, the unlucky chewer would end up biting more tongue than burrito.
Duke University researchers have used a sophisticated tracing technique in mice to map the underlying brain circuitry that keeps mealtime relatively painless. The study, ...
Climate engineering can't erase climate change
2014-06-03
Tinkering with climate change through climate engineering isn't going to help us get around what we have to do says a new report authored by researchers at six universities, including Simon Fraser University.
After evaluating a range of possible climate-altering approaches to dissipating greenhouse gases and reducing warming, the interdisciplinary team concluded there's no way around it. We have to reduce the amount of carbon being released into the atmosphere.
"Some climate engineering strategies look very cheap on paper. But when you consider other criteria, like ...
Fatty liver disease prevented in mice
2014-06-03
Studying mice, researchers have found a way to prevent nonalcoholic fatty liver disease, the most common cause of chronic liver disease worldwide. Blocking a path that delivers dietary fructose to the liver prevented mice from developing the condition, according to investigators at Washington University School of Medicine in St. Louis.
The study appears in a recent issue of the Journal of Biological Chemistry.
In people, nonalcoholic fatty liver disease often accompanies obesity, elevated blood sugar, high blood pressure and other markers of metabolic syndrome. Some ...
Researchers shut down a SARS cloaking system; findings could lead to SARS, MERS vaccines
2014-06-03
WEST LAFAYETTE, Ind. —A Purdue University-led research team has figured out how to disable a part of the SARS virus responsible for hiding it from the immune system; a critical step in developing a vaccine against the deadly disease.
The findings also have potential applications in the creation of vaccines against other coronaviruses, including MERS, said Andrew Mesecar, who led the research.
"This is a first step toward creating a weakened and safe virus for use in an attenuated live vaccine," said Mesecar, Purdue's Walther Professor of Cancer Structural Biology and ...
Study finds coordinated approach improves quality of primary care
2014-06-03
NEW YORK (June 2, 2014) -- Primary care doctors practicing in a model of coordinated, team-based care that leverages health information technology are more likely to give patients recommended preventive screening and appropriate tests than physicians working in other settings, according to research published today in the Annals of Internal Medicine. The study comparing quality of care by physicians using a delivery model known as the patient-centered medical home (PCMH) to care from physicians in non-PCMH practices provides evidence that the previously unproven but popular ...
Progress on detecting glucose levels in saliva
2014-06-03
PROVIDENCE, R.I. [Brown University] — Researchers from Brown University have developed a new biochip sensor that can selectively measure concentrations of glucose in a complex solution similar to human saliva. The advance is an important step toward a device that would enable people with diabetes to test their glucose levels without drawing blood.
The new chip makes use of a series of specific chemical reactions combined with plasmonic interferometry, a means of detecting chemical signature of compounds using light. The device is sensitive enough to detect differences ...
Hubble unveils a colorful view of the universe
2014-06-03
Prior to this survey, astronomers were in a curious position. They knew a lot about star formation occurring in nearby galaxies thanks to UV telescope facilities such as NASA's Galex observatory, which operated from 2003 to 2013. And, thanks to Hubble's near-infrared and visible capability, they had also studied star birth in the most distant galaxies. We see these distant galaxies in their most primitive stages due to the vast amount of time it takes their light to reach us.
However, between 5 and 10 billion light-years away from us -- corresponding to a time period ...
Story tips from the Department of Energy's Oak Ridge National Laboratory, June 2014
2014-06-03
BIOMETRICS – The eyes have it . . .
By discovering and quantifying the "limbus effect," Oak Ridge National Laboratory researchers have advanced the state of the art for human iris recognition systems. While the iris is a proven and reliable biometric for verification or identification, non-ideal images -- such as those captured off axis -- are problematic. Reasons include cornea refraction and the limbus effect, causing iris recognition performance to decrease and in many cases fail entirely. Now, using an anatomically accurate human eye model and some slick math, a ...
LAST 30 PRESS RELEASES:
UT San Antonio School of Public Health: The People’s School
‘Preventable deaths will continue’ without action to make NHS more accessible for autistic people, say experts
Scientists shoot lasers into brain cells to uncover how illusions work
Your ecosystem engineer was a dinosaur
New digital cognitive test for diagnosing Alzheimer's disease
Parents of children with health conditions less confident about a positive school year
New guideline standardizes consent for research participants in Canada
Research as reconciliation: Oil sands and health
AI risks overwriting history and the skills of historians have never been more important, leading academic outlines in new paper
The Lancet Diabetes & Endocrinology: Higher doses of semaglutide can safely enhance weight loss and improve health for adults living with obesity, two new clinical trials confirm
Trauma focused therapy shows promise for children struggling with PTSD
School meals could drive economic growth and food system transformation
Home training for cerebellar ataxias
Dry eyes affect over half the general population, yet only a fifth receive diagnosis and treatment
Researchers sound warning about women with type 2 diabetes taking oral HRT
Overweight and obesity don’t always increase the risk of an early death, Danish study finds
Cannabis use associated with a quadrupling of risk of developing type 2 diabetes, finds study of over 4 million adults
Gestational diabetes linked to cognitive decline in mothers and increased risk of developmental delays, ADHD and autism among children
Could we use eye drops instead of reading glasses as we age?
Patients who had cataracts removed or their eyesight corrected with a new type of lens have good vision over all distances without spectacles
AI can spot which patients need treatment to prevent vision loss in young adults
Half of people stop taking popular weight-loss drug within a year, national study finds
Links between diabetes and depression are similar across Europe, study of over-50s in 18 countries finds
Smoking increases the risk of type 2 diabetes, regardless of its characteristics
Scientists trace origins of now extinct plant population from volcanically active Nishinoshima
AI algorithm based on routine mammogram + age can predict women’s major cardiovascular disease risk
New hurdle seen to prostate screening: primary-care docs
MSU researchers explore how virtual sports aid mental health
Working together, cells extend their senses
Cheese fungi help unlock secrets of evolution
[Press-News.org] 2-D transistors promise a faster electronics futureBerkeley Lab researchers create the first fully 2-D field effect transistors