Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

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

Iranian Experts Clean Uranium-Contaminated Water by Nano-Particles November 23rd, 2014

Novel Method Found for Connection of Metallic Alloys to Polymers November 23rd, 2014

New research project supports internationalisation in nano-research: Launch of new “Baltic Sea Network” November 22nd, 2014

3rd Iran-Proposed Nano Standard Approved by International Standard Organization November 22nd, 2014

Laboratories

NRL Scientists Discover Novel Metamaterial Properties within Hexagonal Boron Nitride November 20th, 2014

Brookhaven Science Associates Awarded Brookhaven Lab Management Contract Battelle/Stony Brook University partnership retains contract it has held since 1998 November 13th, 2014

SUNY Poly Student Awarded Fellowship with the U.S. Department of Energy's Postgraduate Research Program: Ph.D. Candidate Accepts Postmaster's Appointment To Conduct Research At Albany NanoTech Complex November 13th, 2014

Graphene

Graphene/nanotube hybrid benefits flexible solar cells: Rice University labs create novel electrode for dye-sensitized cells November 17th, 2014

Graphene Frontiers Partners with Madico to Accelerate Material Production: Deal to ignite and fulfill demand for industrial scale graphene film that supports energy, consumer electronics, membranes/filtration, solar and other applications November 12th, 2014

Physics

Researchers discern the shapes of high-order Brownian motions November 17th, 2014

Govt.-Legislation/Regulation/Funding/Policy

New research project supports internationalisation in nano-research: Launch of new “Baltic Sea Network” November 22nd, 2014

3rd Iran-Proposed Nano Standard Approved by International Standard Organization November 22nd, 2014

NMTI announces breakthrough solutions for HAMR nanoantenna for next-generation ultra-high density magnetic storage November 21st, 2014

Quantum mechanical calculations reveal the hidden states of enzyme active sites November 20th, 2014

Chip Technology

Nanometrics Announces Upcoming Investor Events November 19th, 2014

A novel method for identifying the body’s ‘noisiest’ networks November 19th, 2014

Researchers create & control spin waves, lifting prospects for enhanced info processing November 17th, 2014

VDMA Electronics Production Equipment: Growth track for 2014 and 2015 confirmed: Business climate survey shows robust industry sector November 14th, 2014

Discoveries

Iranian Experts Clean Uranium-Contaminated Water by Nano-Particles November 23rd, 2014

Novel Method Found for Connection of Metallic Alloys to Polymers November 23rd, 2014

NMTI announces breakthrough solutions for HAMR nanoantenna for next-generation ultra-high density magnetic storage November 21st, 2014

Nano Sorbents Able to Remove Pollutions Caused by Oil Derivatives November 20th, 2014

Announcements

Iranian Experts Clean Uranium-Contaminated Water by Nano-Particles November 23rd, 2014

Novel Method Found for Connection of Metallic Alloys to Polymers November 23rd, 2014

New research project supports internationalisation in nano-research: Launch of new “Baltic Sea Network” November 22nd, 2014

3rd Iran-Proposed Nano Standard Approved by International Standard Organization November 22nd, 2014

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

Iranian Experts Clean Uranium-Contaminated Water by Nano-Particles November 23rd, 2014

Novel Method Found for Connection of Metallic Alloys to Polymers November 23rd, 2014

NMTI announces breakthrough solutions for HAMR nanoantenna for next-generation ultra-high density magnetic storage November 21st, 2014

Nano Sorbents Able to Remove Pollutions Caused by Oil Derivatives November 20th, 2014

Military

NRL Scientists Discover Novel Metamaterial Properties within Hexagonal Boron Nitride November 20th, 2014

Two sensors in one: Nanoparticles that enable both MRI and fluorescent imaging could monitor cancer, other diseases November 18th, 2014

Researchers create & control spin waves, lifting prospects for enhanced info processing November 17th, 2014

Penn engineers efficiently 'mix' light at the nanoscale November 17th, 2014

Research partnerships

Novel Method Found for Connection of Metallic Alloys to Polymers November 23rd, 2014

New research project supports internationalisation in nano-research: Launch of new “Baltic Sea Network” November 22nd, 2014

Quantum mechanical calculations reveal the hidden states of enzyme active sites November 20th, 2014

UO-industry collaboration points to improved nanomaterials: University of Oregon microscope puts spotlight on the surface structure of quantum dots for designing new solar devices November 20th, 2014

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







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE