Navigation Links
Bilayer graphene gets a bandgap
Date:6/11/2009

cally doped by adsorbed metal atoms. But such chemical doping is uncontrolled and not compatible with device applications.

"Creating and especially controlling a bandgap in bilayer graphene has been an outstanding goal," says Wang. "Unfortunately chemical doping is difficult to control."

Researchers then tried to tune the bilayer graphene bandgap by doping the substrate electrically instead of chemically, using a perpendicularly applied, continuously tunable electrical field. But when such a field is applied with a single gate (electrode), the bilayer becomes insulating only at temperatures below one degree Kelvin, near absolute zero suggesting a bandgap value much lower than predicted by theory.

Says Wang, "With these results it was hard to understand exactly what was happening electronically, or why."

Wang and his colleagues made two key decisions that led to their successful attempt to introduce and determine a bandgap in bilayer graphene. The first was to build a two-gated bilayer device, fabricated by Yuanbo Zhang and Tsung-Ta Tang of the UC Berkeley Department of Physics, which allowed the team to independently adjust the electronic bandgap and the charge doping.

The device was a dual-gated field-effect transistor (FET), a type of transistor that controls the flow of electrons from a source to a drain with electric fields shaped by the gate electrodes. Their nano-FET used a silicon substrate as the bottom gate, with a thin insulating layer of silicon dioxide between it and the stacked graphene layers. A transparent layer of aluminum oxide (sapphire) lay over the graphene bilayer; on top of that was the top gate, made of platinum.

The other key decision the researchers made was to get a better grasp of what was really going on in the device as they varied the voltage. Rather than try to measure the bandgap by measuring the device's electrical resistance, or transport, they decided to measure its optical t
'/>"/>

Contact: Paul Preuss
paul_preuss@lbl.gov
510-486-6249
DOE/Lawrence Berkeley National Laboratory
Source:Eurekalert  

Page: 1 2 3 4

Related biology technology :

1. Graphene may have advantages over copper for IC interconnects at the nanoscale
2. Graphene yields secrets to its extraordinary properties
3. Scientists prove graphenes edge structure affects electronic properties
4. Light-speed nanotech: Controlling the nature of graphene
5. Researchers discover method for mass production of nanomaterial graphene
6. New graphene-based material clarifies graphite oxide chemistry
7. Graphene pioneers follow in Nobel footsteps
8. Penn scientists demonstrate potential of graphene films as next-generation transistors
9. By adding graphene, researchers create superior polymer
10. Graphene-based gadgets may be just years away
11. Graphene used to create worlds smallest transistor
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Bilayer graphene gets a bandgap
(Date:8/23/2014)... (PRWEB) August 23, 2014 ... Partners LLC announced today that Janet B. Arrowsmith, ... Expert consultant. NDA Partners Premier Experts are top ... them to bring extraordinary value to the company’s ... critical solutions to help clients successfully develop their ...
(Date:8/22/2014)... (PRWEB) August 23, 2014 This ... current state of the Papain industry in Global ... of the industry, including definitions, applications and industry ... market analysis are provided with a focus on ... market. A comparison between the international and Chinese ...
(Date:8/22/2014)... Today the Academy of Model Aeronautics (AMA) filed a ... for the D.C. Circuit challenging the FAA’s Interpretation of the ... on June 25, 2014. , The AMA believes that ... intent of the FAA Modernization and Reform Act of 2012, ... new rules or regulations regarding model aircraft that are operated ...
(Date:8/22/2014)... 22, 2014 /PRNewswire/ - BIOREM Inc. (TSXV: BRM) ("Biorem" or "the Company") ... June 30, 2014.  Biorem,s complete 2014 second quarter financial statements and MD&A ... ended June 30, , Six-months ended June 30, ... , 2013 , 2014 , 2013 Revenue ... , 9,195 Gross profit , 56 , 1,485 ...
Breaking Biology Technology:Noted Epidemiologist and Former FDA Deputy Director Janet B. Arrowsmith, MD, Joins NDA Partners as a Premier Expert Consultant 2Papain Industry Global & China Development Trend and Proposals Analysis Research Report Available at DeepResearchReports.com 2Papain Industry Global & China Development Trend and Proposals Analysis Research Report Available at DeepResearchReports.com 3AMA Files Petition for Review of FAA’s Interpretive Rule 2Biorem Reports 2014 Second Quarter Results 2Biorem Reports 2014 Second Quarter Results 3
... ... as Of Counsel in its Intellectual Property Group and will be practicing primarily out of ... matters. , ... January 13, 2010 -- Today Preti Flaherty announced that Wayne Keown ...
... , 18-year track ... companies, including cellulosic ethanol pioneer Verenium Corporation , ... Inc., a leading developer of second-generation technology solutions for the ... today that John McCarthy has joined the company ...
... , ST. LOUIS , Jan. 13 ... Group (Nasdaq: SIAL ), today announced the completion of an ... and logistics facility in Steinheim, Germany . The dedicated food-grade ... of Baking) audit, supports customers in Europe and ...
Cached Biology Technology:Attorney Wayne Keown Joins Preti Flaherty's Portland, ME Office 2Biofuels Technology Leader Qteros Names Industry Veteran John McCarthy President and Chief Executive Officer 2Biofuels Technology Leader Qteros Names Industry Veteran John McCarthy President and Chief Executive Officer 3SAFC(R) Enhances World-Class European Storage, Packaging and Distribution Facility to Further Support Food-Grade Certified Products 2SAFC(R) Enhances World-Class European Storage, Packaging and Distribution Facility to Further Support Food-Grade Certified Products 3SAFC(R) Enhances World-Class European Storage, Packaging and Distribution Facility to Further Support Food-Grade Certified Products 4
(Date:8/22/2014)... DUBLIN , August 22, 2014 ... Markets ( http://www.researchandmarkets.com/research/mtm27l/biometrics_market ) has announced the ... North America 2014-2018"  report to their ... , , ,Biometrics is a technology ... individuals based on their physical or ...
(Date:8/22/2014)... , a leading source of information for businesses and ... California, Riverside in its 2014 list of "some of ... To generate the list, the company analyzed citation data ... work has had enormous impact. , The following UC ... published the greatest number of highly cited papers in ...
(Date:8/22/2014)... presented at the 29th Annual International Papillomavirus Conference ... Therapeutics Inc. combats three types of human papillomavirus, ... all cervical cancer. , When tested in several ... of HPV-16, HPV-18 and HPV-11 cells, according to ... who presented the findings at the Seattle conference. ...
Breaking Biology News(10 mins):Biometrics Market in North America 2014-2018: Key Vendors are 3M Cogent, Cross Match, NEC and Safran SA 2Biometrics Market in North America 2014-2018: Key Vendors are 3M Cogent, Cross Match, NEC and Safran SA 35 UC Riverside scientists among world's most influential scientific minds 2
... WASHINGTON, DC A new analysis by the ... that the U.S. government has spent around $430 million ... the Department of Energy funding a majority of the ... European Union and three individual European countries the ...
... of dust and pollen in the atmosphere may make your ... in clouds, Colorado State University atmospheric scientists have discovered for ... to form precipitation in clouds is linked to the abundance ... study by Paul DeMott and Anthony Prenni, research scientists in ...
... If you think of diabetes onset like an elaborate ... Jolla Institute scientist has unmasked a previously unknown cellular player, ... is a hallmark of both type 1 and type 2 ... Jolla Institute for Allergy & Immunology, who led the team, ...
Cached Biology News:Amount of dust, pollen matters for cloud precipitation, climate change 2Amount of dust, pollen matters for cloud precipitation, climate change 3La Jolla Institute scientist leads team which discovers important new player in diabetes onset 2La Jolla Institute scientist leads team which discovers important new player in diabetes onset 3La Jolla Institute scientist leads team which discovers important new player in diabetes onset 4
... of Molecular Imaging (MI) Software for use ... research and drug discovery applications. The Regulatory ... and Drug Administrations Code of Federal Regulations ... Signatures [21 CFR Part 11]. KODAK MI ...
... Microarrays designed for pathway studies, ... protein (PTB) Studies built on the ... synthesis platform. These microarrays are available ... Peptide Microarray Service. Custom ...
... one mouse-click image analysis software for ... is the solution for high quality ... MicroVigene is empowered with VigeneTechs robust ... regional 2D-curve fitting background correction and ...
fully automated system for the processing of microarrays on microscope slides...
Biology Products: