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:7/10/2014)... Francisco, CA (PRWEB) July 10, 2014 ... family closer together. The Archer Family purchased a ... contained within DNA, but ended up with a lifetime ... discoveries contained within the family members’ DNA genuinely brought ... had decided to search deeper into genetic history and ...
(Date:7/10/2014)... July 10, 2014  Franciscan St. Anthony ... capnography for respiratory monitoring outside the operating ... leaders in embracing state-of-the-art patient safety technology. ... are breathing and can alert medical caregivers ... the amount of carbon dioxide the patient ...
(Date:7/10/2014)... --  Ceres, Inc . (Nasdaq: CERE ), ... results for the three months ended May 31, 2014 ... Ceres reported that the company and its customers have ... in Brazil, which concluded in June, despite dry and ... for part of the growing season. Yields of several ...
(Date:7/10/2014)... Understanding the basis of psychiatric disorders has been extremely ... increase risk but are insufficient to cause disease. Now ... Cell Press journal Cell Stem Cell describe ... genetic risks interact with other risk factors or environmental ... Their research pinpoints a genetic variant that may predispose ...
Breaking Biology Technology:Ancestry DNA Test Reveals a Controversial and Undiscovered Family History 2Ancestry DNA Test Reveals a Controversial and Undiscovered Family History 3Ancestry DNA Test Reveals a Controversial and Undiscovered Family History 4Ancestry DNA Test Reveals a Controversial and Undiscovered Family History 5Franciscan St. Anthony Health-Crown Point Underscores Patient Safety Commitment Through Expanded Use of Capnography 2Ceres Announces Fiscal Third Quarter 2014 Financial Results 2Ceres Announces Fiscal Third Quarter 2014 Financial Results 3Ceres Announces Fiscal Third Quarter 2014 Financial Results 4Ceres Announces Fiscal Third Quarter 2014 Financial Results 5Ceres Announces Fiscal Third Quarter 2014 Financial Results 6Ceres Announces Fiscal Third Quarter 2014 Financial Results 7Ceres Announces Fiscal Third Quarter 2014 Financial Results 8Ceres Announces Fiscal Third Quarter 2014 Financial Results 9New strategy could uncover genes at the root of psychiatric illnesses 2
... oncology intelligence initiative powered by The Arcas Group, announced ... following this month,s annual meeting of the American Society ... expand on previous Quick Polls carried out after the ... efforts after the American Society of Hematology (ASH) annual ...
... Incorporated (NASDAQ: SPEX ) -- an ... syndrome and atherosclerosis, and providers of technical and ... pharmaceutical companies -- today announced that its Annual ... will be held on Tuesday, November 15, 2011, ...
... 2011 ,   ... that its,US-subsidiary NextGen Sciences Inc, a leader in ... cerebrospinal,fluid (CSF) multiple protein (multiplex) assay, csf ... qualification . The assay simultaneously measures,43 human CSF ...
Cached Biology Technology:MDOUTLOOK® 4th Annual Quick Polls From ASCO 2011: Report on Clinical Impact of New Developments in Cancer Therapeutics 2MDOUTLOOK® 4th Annual Quick Polls From ASCO 2011: Report on Clinical Impact of New Developments in Cancer Therapeutics 3Spherix Announces Annual Shareholders Meeting Date 2NextGen Sciences Launches Multiple Protein cerebrospinal fluid (CSF) CNS Disease Biomarker Assay 2NextGen Sciences Launches Multiple Protein cerebrospinal fluid (CSF) CNS Disease Biomarker Assay 3
(Date:7/11/2014)... is evidence that under the normal circumstances, ... development, maintain neuronal environment, and exhibit therapeutic ... neurodegenerative disease. Previous studies have found that ... after chemical induction have reduced viability, which ... Prof. Xiaodong Yuan, Kailuan General Hospital, Hebei ...
(Date:7/10/2014)... Fe, Albuquerque, and other major cities in New Mexico, ... treated municipal wastewater rather than precious potable water supplies. ... 40% of all golf courses receive treated effluent. Reusing ... , Additionally, golf courses and homeowners alike fertilize their ... fertilizer is nitrate. A New Mexico State University turfgrass ...
(Date:7/10/2014)... 2014  Unisys Corporation,s (NYSE: UIS ) subsidiary ... today announced that it has been selected by the Dutch ... new Basic Provision Biometrics solution for penitentiaries across ... contract with a solution based on its open standards-based ... the contract is up to seven years, with the new ...
Breaking Biology News(10 mins):'Tailored' water -- the latest in lawn care 2Unisys Delivers New Basic Provision Biometrics Solution to Dutch Custodial Institutions Service 2Unisys Delivers New Basic Provision Biometrics Solution to Dutch Custodial Institutions Service 3
... in the online edition of Physiological Genomics finds that individuals ... The study offers the first evidence of the role that ... controls sugar entry into the cells has on sugar ... in sugar. The study was conducted by Ahmed ...
... to Critical Data with MobileCop(R) ... ... International Inc.,(OTC Bulletin Board: BKYI), a leader in finger-based biometric,identification and ... Baltimore (MD) Police Department ("BPD"),for additional licenses of BIO-key,s MobileCop software ...
... new ways to stop the progression of cancer, researchers ... discovered a compound that has shown to prevent cancer ... Gene Regulation and Systems Biology. The compound, which ... normal cells from turning into cancer cells and inhibited ...
Cached Biology News:Genetic variation linked to sugary food 2Genetic variation linked to sugary food 3BIO-key(R) Receives $335,000 Contract Award From Baltimore Police 2BIO-key(R) Receives $335,000 Contract Award From Baltimore Police 3Chemical compound prevents cancer in lab 2
... GeneBLAzer cell-based assays utilize the ... of the negatively charged fluorescent beta-lactamase ... esters readily enter the cell, where ... converts them into their negatively charged ...
Src cDNA Expression Kit (wild type)...
1M stock solution (238mg/ml)...
Homogenizing Solution, 18ml Proteinase K - [50ug/l] 75 l...
Biology Products: