Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button


DHgate

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

JPK reports on the use of a NanoWizard AFM system at the University of Kaiserslautern to study the interaction of bacteria with microstructured surfaces April 28th, 2016

University of Illinois researchers create 1-step graphene patterning method April 27th, 2016

Nanograft seeded with 3 cell types promotes blood vessel formation to speed wound healing April 27th, 2016

NREL finds nanotube semiconductors well-suited for PV systems April 27th, 2016

Danish researchers behind vaccine breakthrough April 27th, 2016

Graphene/ Graphite

University of Illinois researchers create 1-step graphene patterning method April 27th, 2016

Atomic magnets using hydrogen and graphene April 27th, 2016

Laboratories

NREL finds nanotube semiconductors well-suited for PV systems April 27th, 2016

NREL theory establishes a path to high-performance 2-D semiconductor devices April 27th, 2016

Brookhaven's Oleg Gang Named a Battelle 'Inventor of the Year': Recognized for work using DNA to guide and regulate the self-assembly of nanoparticles into clusters and arrays with controllable properties April 25th, 2016

Physics

Physicists detect the enigmatic spin momentum of light April 26th, 2016

Rare Earth atoms see the light: Physicist Dirk Bouwmeester discovers a promising route for combined optical and solid state-based quantum information processing April 25th, 2016

Atoms placed precisely in silicon can act as quantum simulator April 24th, 2016

Govt.-Legislation/Regulation/Funding/Policy

NREL finds nanotube semiconductors well-suited for PV systems April 27th, 2016

NREL theory establishes a path to high-performance 2-D semiconductor devices April 27th, 2016

Researchers create artificial protein to control assembly of buckyballs April 27th, 2016

Chemists use DNA to build the world's tiniest thermometer April 27th, 2016

Chip Technology

University of Illinois researchers create 1-step graphene patterning method April 27th, 2016

NREL theory establishes a path to high-performance 2-D semiconductor devices April 27th, 2016

Atomic magnets using hydrogen and graphene April 27th, 2016

The light stuff: A brand-new way to produce electron spin currents - Colorado State University physicists are the first to demonstrate using non-polarized light to produce a spin voltage in a metal April 26th, 2016

Discoveries

Nanograft seeded with 3 cell types promotes blood vessel formation to speed wound healing April 27th, 2016

NREL finds nanotube semiconductors well-suited for PV systems April 27th, 2016

Danish researchers behind vaccine breakthrough April 27th, 2016

NREL theory establishes a path to high-performance 2-D semiconductor devices April 27th, 2016

Announcements

JPK reports on the use of a NanoWizard AFM system at the University of Kaiserslautern to study the interaction of bacteria with microstructured surfaces April 28th, 2016

University of Illinois researchers create 1-step graphene patterning method April 27th, 2016

Researchers create artificial protein to control assembly of buckyballs April 27th, 2016

Chemists use DNA to build the world's tiniest thermometer April 27th, 2016

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

Danish researchers behind vaccine breakthrough April 27th, 2016

NREL theory establishes a path to high-performance 2-D semiconductor devices April 27th, 2016

Atomic magnets using hydrogen and graphene April 27th, 2016

Researchers create artificial protein to control assembly of buckyballs April 27th, 2016

Military

Nanograft seeded with 3 cell types promotes blood vessel formation to speed wound healing April 27th, 2016

The light stuff: A brand-new way to produce electron spin currents - Colorado State University physicists are the first to demonstrate using non-polarized light to produce a spin voltage in a metal April 26th, 2016

NRL reveals novel uniform coating process of p-ALD April 21st, 2016

Team builds first quantum cascade laser on silicon: Eliminates the need for an external light source for mid-infrared silicon photonic devices or photonic circuits April 21st, 2016

Research partnerships

Nanograft seeded with 3 cell types promotes blood vessel formation to speed wound healing April 27th, 2016

NREL finds nanotube semiconductors well-suited for PV systems April 27th, 2016

Flipping a chemical switch helps perovskite solar cells beat the heat April 26th, 2016

XEI Scientific and the University of Southern California collaborate on the use of downstream plasma cleaning in sample preparation and publish a paper in ACS Photonics April 26th, 2016

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







Car Brands
Buy website traffic