Home > Press > Laser technique could unlock use of tough material for next-generation electronics: Researchers make graphene tunable, opening up its band gap to a record 2.1 electronvolts
Graphene, a super tough wonder material, hasn't made it into electronics yet because it doesn't conduct an electric current on its own. Researchers used a laser technique to permanently stress graphene into a structure that allows the flow of electric current. CREDIT Purdue University image/Gary Cheng |
Abstract:
ABSTRACT
Asymmetric 3D Elastic-Plastic Strain-Modulated Electron Energy Structure in Monolayer Graphene by Laser Shocking
Maithilee Motlag1, Prashant Kumar1, Kevin Y. Hu1, Shengyu Jin1, Ji Li1, Jiayi Shao1, Xuan Yi1, Yen-Hsiang Lin2, Jenna C. Walrath2, Lei Tong3, Xinyu Huang3, Rachel S. Goldman2, Lei Ye3, and Gary J. Cheng1
1Purdue University, West Lafayette, IN, USA
2University of Michigan, Ann Arbor, MI, USA
3Huazhong University of Science and Technology, Wuhan, China
doi: 10.1002/adma.201900597
Graphene has a great potential to replace silicon in prospective semiconductor industries due to its outstanding electronic and transport properties; nonetheless, its lack of energy bandgap is a substantial limitation for practical applications. To date, straining graphene to break its lattice symmetry is perhaps the most efficient approach toward realizing bandgap tunability in graphene. However, due to the weak lattice deformation induced by uniaxial or in?plane shear strain, most strained graphene studies have yielded bandgaps <1 eV. In this work, a modulated inhomogeneous local asymmetric elastic-plastic straining is reported that utilizes GPa?level laser shocking at a high strain rate (dε/dt) ? 106-107 s?1, with excellent formability, inducing tunable bandgaps in graphene of up to 2.1 eV, as determined by scanning tunneling spectroscopy. High?resolution imaging and Raman spectroscopy reveal strain?induced modifications to the atomic and electronic structure in graphene and first?principles simulations predict the measured bandgap openings. Laser shock modulation of semimetallic graphene to a semiconducting material with controllable bandgap has the potential to benefit the electronic and optoelectronic industries.
In 2004, researchers discovered a super thin material that is at least a 100 times stronger than steel and the best known conductor of heat and electricity.
This means that the material, graphene, could bring faster electronics than is possible today with silicon.
But to truly be useful, graphene would need to carry an electric current that switches on and off, like what silicon does in the form of billions of transistors on a computer chip. This switching creates strings of 0s and 1s that a computer uses for processing information.
Purdue University researchers, in collaboration with the University of Michigan and the Huazhong University of Science and Technology, show how a laser technique could permanently stress graphene into having a structure that allows the flow of electric current.
This structure is a so-called "band gap." Electrons need to jump across this gap in order to become conduction electrons, which makes them capable of carrying electric current. But graphene doesn't naturally have a band gap.
Purdue researchers created and widened the band gap in graphene to a record 2.1 electronvolts. To function as a semiconductor such as silicon, the band gap would need to be at least the previous record of 0.5 electronvolts.
"This is the first time that an effort has achieved such high band gaps without affecting graphene itself, such as through chemical doping. We have purely strained the material," said Gary Cheng, professor of industrial engineering at Purdue, whose lab has investigated various ways to make graphene more useful for commercial applications.
The presence of a band gap allows semiconductor materials to switch between insulating or conducting an electric current, depending on whether their electrons are pushed across the band gap or not.
Surpassing 0.5 electronvolts unlocks even more potential for graphene in next-generation electronic devices, the researchers say. Their work appears in an issue of Advanced Materials.
"Researchers in the past opened the band gap by simply stretching graphene, but stretching alone doesn't widen the band gap very much. You need to permanently change the shape of graphene to keep the band gap open," Cheng said.
Cheng and his collaborators not only kept the band gap open in graphene, but also made it to where the gap width could be tuned from zero to 2.1 electronvolts, giving scientists and manufacturers the option to just use certain properties of graphene depending on what they want the material to do.
The researchers made the band gap structure permanent in graphene using a technique called laser shock imprinting, which Cheng developed in 2014 along with scientists at Harvard University, the Madrid Institute for Advanced Studies and the University of California, San Diego.
For this study, the researchers used a laser to create shockwave impulses that penetrated an underlying sheet of graphene. The laser shock strains graphene onto a trench-like mold - permanently shaping it. Adjusting the laser power adjusts the band gap.
While still far from putting graphene into semiconducting devices, the technique grants more flexibility in taking advantage of the material's optical, magnetic and thermal properties, Cheng said.
###
The work was supported by multiple entities, including the National Science Foundation (Grant numbers CMMI-0547636 and CMMI 0928752) and the National Research Council Senior Research Associateship.
####
For more information, please click here
Contacts:
Kayla Wiles
765-494-2432
Copyright © Purdue University
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.
Related Links |
Related News Press |
News and information
Researchers develop artificial building blocks of life March 8th, 2024
Graphene/ Graphite
NRL discovers two-dimensional waveguides February 16th, 2024
2 Dimensional Materials
NRL discovers two-dimensional waveguides February 16th, 2024
Magnetism/Magnons
Three-pronged approach discerns qualities of quantum spin liquids November 17th, 2023
Study on Magnetic Force Microscopy wins 2023 Advances in Magnetism Award: Analysis of finite size effects reveals significant consequences for density measurements November 3rd, 2023
Twisted science: NIST researchers find a new quantum ruler to explore exotic matter October 6th, 2023
Govt.-Legislation/Regulation/Funding/Policy
What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024
Researchers’ approach may protect quantum computers from attacks March 8th, 2024
Optically trapped quantum droplets of light can bind together to form macroscopic complexes March 8th, 2024
Possible Futures
Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024
Chip Technology
New chip opens door to AI computing at light speed February 16th, 2024
HKUST researchers develop new integration technique for efficient coupling of III-V and silicon February 16th, 2024
NRL discovers two-dimensional waveguides February 16th, 2024
Nanoelectronics
Interdisciplinary: Rice team tackles the future of semiconductors Multiferroics could be the key to ultralow-energy computing October 6th, 2023
Key element for a scalable quantum computer: Physicists from Forschungszentrum Jülich and RWTH Aachen University demonstrate electron transport on a quantum chip September 23rd, 2022
Reduced power consumption in semiconductor devices September 23rd, 2022
Atomic level deposition to extend Moore’s law and beyond July 15th, 2022
Discoveries
What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024
Researchers’ approach may protect quantum computers from attacks March 8th, 2024
High-tech 'paint' could spare patients repeated surgeries March 8th, 2024
Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024
Materials/Metamaterials/Magnetoresistance
Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024
Focused ion beam technology: A single tool for a wide range of applications January 12th, 2024
Announcements
What heat can tell us about battery chemistry: using the Peltier effect to study lithium-ion cells March 8th, 2024
Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024
Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers/Posters
Researchers develop artificial building blocks of life March 8th, 2024
Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024
Photonics/Optics/Lasers
Nanoscale CL thermometry with lanthanide-doped heavy-metal oxide in TEM March 8th, 2024
Optically trapped quantum droplets of light can bind together to form macroscopic complexes March 8th, 2024
HKUST researchers develop new integration technique for efficient coupling of III-V and silicon February 16th, 2024
A battery’s hopping ions remember where they’ve been: Seen in atomic detail, the seemingly smooth flow of ions through a battery’s electrolyte is surprisingly complicated February 16th, 2024
Research partnerships
Researchers’ approach may protect quantum computers from attacks March 8th, 2024
'Sudden death' of quantum fluctuations defies current theories of superconductivity: Study challenges the conventional wisdom of superconducting quantum transitions January 12th, 2024
Development of zinc oxide nanopagoda array photoelectrode: photoelectrochemical water-splitting hydrogen production January 12th, 2024
The latest news from around the world, FREE | ||
Premium Products | ||
Only the news you want to read!
Learn More |
||
Full-service, expert consulting
Learn More |
||