Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > New rapid synthesis developed for bilayer graphene and high-performance transistors: UCSB researchers demonstrate ultra-fast and deterministic growth of high-quality and large-area bilayer graphene films with controlled stacking order required for low-power digital electronics

This is concept art of a schematic view of an AB-stacked graphene film synthesized by UC Santa Barbara researchers using a stoichiometry engineered bifunctional alloy catalyst.

Credit: Peter Allen, UCSB
This is concept art of a schematic view of an AB-stacked graphene film synthesized by UC Santa Barbara researchers using a stoichiometry engineered bifunctional alloy catalyst.

Credit: Peter Allen, UCSB

Abstract:
Researchers at University of California, Santa Barbara, in collaboration with Rice University, have recently demonstrated a rapid synthesis technique for large-area Bernal (or AB) stacked bilayer graphene films that can open up new pathways for digital electronics and transparent conductor applications.

New rapid synthesis developed for bilayer graphene and high-performance transistors: UCSB researchers demonstrate ultra-fast and deterministic growth of high-quality and large-area bilayer graphene films with controlled stacking order required for low-power digital electronics

Santa Barbara, CA | Posted on May 3rd, 2014

The invention also includes the first demonstration of a bilayer graphene double-gate field-effect transistor (FET), showing record ON/OFF transistor switching ratio and carrier mobility that could drive future ultra-low power and low-cost electronics.

Graphene is the thinnest known (~0.5 nanometer per layer) 2-dimensional atomic crystal. It has attracted wide interest due to its promising electrical and thermal properties and potential applications in electronics and photonics. However, many of those applications are significantly restricted by the zero band gap of graphene that results in leaky transistors not suitable for digital electronics.

"In addition to its atomically smooth surfaces, a considerable band gap of up to ~0.25 eV can be opened up in bilayer graphene by creating a potential difference between the two layers, and thereby breaking the inherent symmetry, if the two layers can be aligned along a certain (Bernal or AB) orientation" explained Kaustav Banerjee, professor of electrical and computer engineering and Director of the Nanoelectronics Research Lab at UCSB. "The dual-gated transistors were specifically designed to allow such potential difference to be established between the layers through one of the gates, while the second gate modulated the carriers in the channel," he added. Banerjee's research team also includes UCSB researchers Wei Liu, Stephan Kraemer, Deblina Sarkar, Hong Li and Professor Pulickel Ajayan of Rice University. Their study was recently published in Chemistry of Materials.

The graphene films were grown in a deterministic manner using an engineered bifunctional (Cu:Ni) alloy surface at a relatively low temperature of 920 C. Large-area (> 3 inch 3 inch) Bernal (or AB) stacked bilayer graphene growth was demonstrated within few minutes and with nearly 100% area coverage. The bilayer graphene films exhibited electron mobility as high as 3450 cm2/(Vs), which is comparable to that of exfoliated bilayer graphene, thereby confirming very high-quality. The quality of grown graphene was further corroborated by demonstration of high-performance FETs with record ON/OFF ratio that is a key requirement in low-power digital electronics.

"Achieving surface catalytic graphene growth mode and precise control of the surface carbon concentration were key factors for the favorable growth kinetics for AB stacked bilayer graphene," explained Wei Liu, a post-doctoral researcher in Banerjee's group and a co-author of the article. In 2011, Banerjee's group demonstrated a large-area monolayer graphene synthesis method using a copper substrate as catalyst.

Bilayer graphene is close to monolayer graphene in terms of the film thickness with a hexagonal atomic structure and can be derived from its layered bulk form (graphite) in which adjacent layers are held together by relatively weak van der Waals forces. "However, apart from its band gap tunability, bilayer graphene has some key advantages over monolayer graphene. It has higher density of states and suffers much less from interface effects, which are beneficial for improving the current carrying capability," Liu continued.

"This demonstration is very impressive and should have far-reaching implications for the entire 2D materials community," commented Professor Ali Javey, of University of California, Berkeley and a Co-Director of the Bay Area Photovoltaic Consortium (BAPVC).

###

Their research was supported by the Bay Area Photovoltaic Consortium (BAPVC) a U.S. Department of Energy funded Photovoltaic Consortium, the California NanoSystems Institute at UC Santa Barbara, and the Materials Research Laboratory at UCSB: a National Science Foundation MRSEC.

####

About University of California - Santa Barbara
The College of Engineering at University of California, Santa Barbara is recognized globally as a leader among the top tier of engineering education and research programs, and is renowned for a successful interdisciplinary approach to engineering research. www.engineering.ucsb.edu

For more information, please click here

Contacts:
Melissa Van De Werfhorst

Copyright © University of California - Santa Barbara

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Surfing a wake of light: Researchers observe and control light wakes for the first time July 6th, 2015

Tel Aviv/Tsinghua University project uses crowd computing to improve water filtration: The research, a product of the new TAU-Tsinghua XIN Center, was conducted by 150,000 volunteers at IBM's World Community Grid July 6th, 2015

Transition from 3 to 2 dimensions increases conduction, MIPT scientists discover July 6th, 2015

A Stretchy Mesh Heater for Sore Muscles July 6th, 2015

Graphene

Transition from 3 to 2 dimensions increases conduction, MIPT scientists discover July 6th, 2015

BBC World Service to broadcast Forum discussion on graphene July 6th, 2015

Govt.-Legislation/Regulation/Funding/Policy

Surfing a wake of light: Researchers observe and control light wakes for the first time July 6th, 2015

New technology using silver may hold key to electronics advances July 2nd, 2015

NIST Group Maps Distribution of Carbon Nanotubes in Composite Materials July 2nd, 2015

Ultra-stable JILA microscopy technique tracks tiny objects for hours July 1st, 2015

Chip Technology

Fundamental observation of spin-controlled electrical conduction in metals: Ultrafast terahertz spectroscopy yields direct insight into the building block of modern magnetic memories July 6th, 2015

Transition from 3 to 2 dimensions increases conduction, MIPT scientists discover July 6th, 2015

Nanometrics to Announce Second Quarter Financial Results on July 23, 2015 July 2nd, 2015

The quantum middle man July 2nd, 2015

Nanoelectronics

Transition from 3 to 2 dimensions increases conduction, MIPT scientists discover July 6th, 2015

New technology using silver may hold key to electronics advances July 2nd, 2015

Exagan Raises 5.7 Million to Produce High-efficiency GaN-on-Silicon Power-switching Devices on 200mm Wafers: Leti-and-Soitec Spinout Focused on Becoming Leading European Source Of GaN Devices for Solar, Automotive, Telecoms and Infrastructure June 25th, 2015

Nanowires could be the LEDs of the future June 25th, 2015

Discoveries

Fundamental observation of spin-controlled electrical conduction in metals: Ultrafast terahertz spectroscopy yields direct insight into the building block of modern magnetic memories July 6th, 2015

Surfing a wake of light: Researchers observe and control light wakes for the first time July 6th, 2015

Transition from 3 to 2 dimensions increases conduction, MIPT scientists discover July 6th, 2015

A Stretchy Mesh Heater for Sore Muscles July 6th, 2015

Announcements

Surfing a wake of light: Researchers observe and control light wakes for the first time July 6th, 2015

Tel Aviv/Tsinghua University project uses crowd computing to improve water filtration: The research, a product of the new TAU-Tsinghua XIN Center, was conducted by 150,000 volunteers at IBM's World Community Grid July 6th, 2015

Transition from 3 to 2 dimensions increases conduction, MIPT scientists discover July 6th, 2015

A Stretchy Mesh Heater for Sore Muscles July 6th, 2015

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Fundamental observation of spin-controlled electrical conduction in metals: Ultrafast terahertz spectroscopy yields direct insight into the building block of modern magnetic memories July 6th, 2015

Surfing a wake of light: Researchers observe and control light wakes for the first time July 6th, 2015

Tel Aviv/Tsinghua University project uses crowd computing to improve water filtration: The research, a product of the new TAU-Tsinghua XIN Center, was conducted by 150,000 volunteers at IBM's World Community Grid July 6th, 2015

Transition from 3 to 2 dimensions increases conduction, MIPT scientists discover July 6th, 2015

Research partnerships

Fundamental observation of spin-controlled electrical conduction in metals: Ultrafast terahertz spectroscopy yields direct insight into the building block of modern magnetic memories July 6th, 2015

Surfing a wake of light: Researchers observe and control light wakes for the first time July 6th, 2015

Tel Aviv/Tsinghua University project uses crowd computing to improve water filtration: The research, a product of the new TAU-Tsinghua XIN Center, was conducted by 150,000 volunteers at IBM's World Community Grid July 6th, 2015

Groundbreaking research to help control liquids at micro and nano scales July 3rd, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project