Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Lighting the Way to Graphene-based Devices: Berkeley Lab Researchers Use Light to Dope Graphene Boron Nitride Heterostructures

Semiconductors made from graphene and boron nitride can be charge-doped using light. When the GBN heterostructure is exposed to light (green arrows), positive charges move from the graphene layer (purple) to boron nitride layer (blue).
Semiconductors made from graphene and boron nitride can be charge-doped using light. When the GBN heterostructure is exposed to light (green arrows), positive charges move from the graphene layer (purple) to boron nitride layer (blue).

Abstract:
Graphene continues to reign as the next potential superstar material for the electronics industry, a slimmer, stronger and much faster electron conductor than silicon. With no natural energy band-gap, however, graphene's superfast conductance can't be switched off, a serious drawback for transistors and other electronic devices. Various techniques have been deployed to overcome this problem with one of the most promising being the integration of ultrathin layers of graphene and boron nitride into two-dimensional heterostructures. As conductors, these bilayered hybrids are almost as fast as pure graphene, plus they are well-suited for making devices. However, tailoring the electronic properties of graphene boron nitride (GBN) heterostructures has been a tricky affair, involving chemical doping or electrostatic-gating - until now.

Lighting the Way to Graphene-based Devices: Berkeley Lab Researchers Use Light to Dope Graphene Boron Nitride Heterostructures

Berkeley, CA | Posted on May 18th, 2014

Researchers with Berkeley Lab and the University of California (UC) Berkeley have demonstrated a technique whereby the electronic properties of GBN heterostructures can be modified with visible light. Feng Wang, a condensed matter physicist with Berkeley Lab's Materials Sciences Division and UC Berkeley's Physics Department, as well as an investigator for the Kavli Energy NanoSciences Institute at Berkeley, led a study in which photo-induced doping of GBN heterostructures was used to create p-n junctions and other useful doping profiles while preserving the material's remarkably high electron mobility.

"We've demonstrated that visible light can induce a robust writing and erasing of charge-doping in GBN heterostructures without sacrificing high carrier mobility," Wang says. "The use of visible light gives us incredible flexibility and, unlike electrostatic gating and chemical doping, does not require multi-step fabrication processes that reduce sample quality. Additionally, different patterns can be imparted and erased at will, which was not possible with doping techniques previously used on GBN heterostructures."

Graphene is a single layer of carbon atoms arranged in a hexagonal lattice. Boron nitride is a layered compound that features a similar hexagonal lattice - in fact hexagonal boron nitride is sometimes referred to as "white graphene." Bound together by the relatively weak intermolecular attraction known as the van der Waals force, GBN heterostructures have shown high potential to serve as platforms not only for high-electron-mobility transistors, but also for optoelectronic applications, including photodetectors and photovoltaic cells. The key to future success will be the ability to dope these materials in a commercially scalable manner. The photo-induced modulation doping technique developed by Wang and a large team of collaborators meets this requirement as it is comparable to the photolithography schemes widely used today for mass production in the semiconductor industry. Illumination of a GBN heterostructure even with just an incandescent lamp can modify electron-transport in the graphene layer by inducing a positive-charge distribution in the boron nitride layer that becomes fixed when the illumination is turned off.

"We've shown show that this photo-induced doping arises from microscopically coupled optical and electrical responses in the GBN heterostructures, including optical excitation of defect transitions in boron nitride, electrical transport in graphene, and charge transfer between boron nitride and graphene," Wang says. "This is analogous to the modulation doping first developed for high-quality semiconductors."

While the photo-induced modulation doping of GBN heterostructures only lasted a few days if the sample was kept in darkness - further exposure to light erased the effect - this is not a concern as Wang explains.

"A few days of modulation doping are sufficient for many avenues of scientific inquiry, and for some device applications, the rewritability we can provide is needed more than long term stability," he says. "For the moment, what we have is a simple technique for inhomogeneous doping in a high-mobility graphene material that opens the door to novel scientific studies and applications."

A paper on this research has been published in the journal Nature Nanotechnology entitled "Photoinduced doping in heterostructures of graphene and boron nitride." Co-authors are Long Ju, Jairo Velasco Jr., Edwin Huang, Salman Kahn, Casey Nosiglia, Hsin-Zon Tsai, Wei Yang, Takashi Taniguchi, Kenji Watanabe, Yuanbo Zhang, Guangyu Zhang, Michael Crommie and Alex Zettl.

This research was supported by the U.S. Department of Energy's Office of Science and the Office of Naval Research.

####

For more information, please click here

Contacts:
Lynn Yarris

510-486-5375

Copyright © DOE/Lawrence Berkeley National Laboratory

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 Links

Download article:

For more about the research of Feng Wang go here:

Related News Press

News and information

Looking for the quantum frontier: Beyond classical computing without fault-tolerance? April 27th, 2017

Metal nanoparticles induced visible-light photocatalysis: Mechanisms, applications, ways of promoting catalytic activity and outlook April 27th, 2017

Arrowhead Pharmaceuticals to Webcast Fiscal 2017 Second Quarter Results April 27th, 2017

California Research Alliance by BASF establishes more than 25 research projects in three years April 26th, 2017

Affordable STM32 Cloud-Connectable Kit from STMicroelectronics Puts More Features On-Board for Fast and Flexible IoT-Device Development April 26th, 2017

Laboratories

Video captures bubble-blowing battery in action: Researchers propose how bubbles form, could lead to smaller lithium-air batteries April 26th, 2017

Physics

Geoffrey Beach: Drawn to explore magnetism: Materials researcher is working on the magnetic memory of the future April 25th, 2017

Graphene/ Graphite

Graphene holds up under high pressure: Used in filtration membranes, ultrathin material could help make desalination more productive April 24th, 2017

Two-dimensional melting of hard spheres experimentally unravelled after 60 years: First definitive experimental evidence of two-dimensional melting of hard spheres April 21st, 2017

Researchers “iron out” graphene’s wrinkles: New technique produces highly conductive graphene wafers April 3rd, 2017

New ultrafast flexible and transparent memory devices could herald new era of electronics April 1st, 2017

Govt.-Legislation/Regulation/Funding/Policy

Metal nanoparticles induced visible-light photocatalysis: Mechanisms, applications, ways of promoting catalytic activity and outlook April 27th, 2017

Graphene holds up under high pressure: Used in filtration membranes, ultrathin material could help make desalination more productive April 24th, 2017

Nanoparticle vaccine shows potential as immunotherapy to fight multiple cancer types April 24th, 2017

NanoMONITOR shares its latest developments concerning the NanoMONITOR Software and the Monitoring stations April 21st, 2017

Chip Technology

Geoffrey Beach: Drawn to explore magnetism: Materials researcher is working on the magnetic memory of the future April 25th, 2017

'Neuron-reading' nanowires could accelerate development of drugs for neurological diseases April 12th, 2017

Nanometrics to Announce First Quarter Financial Results on May 2, 2017 April 11th, 2017

AIM Photonics Presents Cutting-Edge Integrated Photonics Technology Developments to Packed House at OFC 2017, the Optical Networking and Communication Conference & Exhibition April 11th, 2017

Discoveries

Looking for the quantum frontier: Beyond classical computing without fault-tolerance? April 27th, 2017

Metal nanoparticles induced visible-light photocatalysis: Mechanisms, applications, ways of promoting catalytic activity and outlook April 27th, 2017

Geoffrey Beach: Drawn to explore magnetism: Materials researcher is working on the magnetic memory of the future April 25th, 2017

Using light to propel water : With new method, MIT engineers can control and separate fluids on a surface using only visible light April 25th, 2017

Announcements

Looking for the quantum frontier: Beyond classical computing without fault-tolerance? April 27th, 2017

Metal nanoparticles induced visible-light photocatalysis: Mechanisms, applications, ways of promoting catalytic activity and outlook April 27th, 2017

Arrowhead Pharmaceuticals to Webcast Fiscal 2017 Second Quarter Results April 27th, 2017

Video captures bubble-blowing battery in action: Researchers propose how bubbles form, could lead to smaller lithium-air batteries April 26th, 2017

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

Looking for the quantum frontier: Beyond classical computing without fault-tolerance? April 27th, 2017

Metal nanoparticles induced visible-light photocatalysis: Mechanisms, applications, ways of promoting catalytic activity and outlook April 27th, 2017

Video captures bubble-blowing battery in action: Researchers propose how bubbles form, could lead to smaller lithium-air batteries April 26th, 2017

Using light to propel water : With new method, MIT engineers can control and separate fluids on a surface using only visible light April 25th, 2017

Military

Nano-SPEARs gently measure electrical signals in small animals: Rice University's tiny needles simplify data gathering to probe diseases, test drugs April 17th, 2017

New technology could offer cheaper, faster food testing: Specialized droplets interact with bacteria and can be analyzed using a smartphone April 7th, 2017

Teri Odom and Richard Van Duyne Honored by Department of Defense: Each will receive $3 million over five years to conduct high-risk, high-payoff research March 31st, 2017

NIST physicists show ion pairs perform enhanced 'spooky action' March 30th, 2017

Research partnerships

California Research Alliance by BASF establishes more than 25 research projects in three years April 26th, 2017

Better living through pressure: Functional nanomaterials made easy April 19th, 2017

Shedding light on the absorption of light by titanium dioxide April 14th, 2017

AIM Photonics Presents Cutting-Edge Integrated Photonics Technology Developments to Packed House at OFC 2017, the Optical Networking and Communication Conference & Exhibition April 11th, 2017

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