- 2019-06-03 15:05:55
- Article ID: 713859
2D crystals conforming to 3D curves create strain for engineering quantum devices
Atomistic simulation mimicing the growth of an MoS2 monolayer on a curved substrate, by sequential addition of rows of atoms to the "growing edge" and relaxation with Stillinger Weber potential. The atoms are colored by the level of biaxial strain with red indicating regions experiencing stretching, and blue indicating compression. Read about the project at http://news.rice.edu/2019/06/03/micro... For more details please see: K. Wang, A. A. Puretzky, Z. Hu, B. R. Srijanto, X. Li, N. Gupta, H. Yu, M. Tian, M. Mahjouri-Samani, X. Gao, A. Oyedele, C. M. Rouleau, G. Eres, B. I. Yakobson, M. Yoon, K. Xiao, D. B. Geohegan, Strain tolerance of two-dimensional crystal growth on curved surfaces. Sci. Adv. 5, eaav4028 (2019).
The team first explored growth of the flat crystals on substrates patterned with sharp steps and trenches. Surprisingly, the crystals conformally grew up and down these flat obstacles without changing their properties or growth rates. However, curvy surfaces required the crystals to stretch as they grew to maintain their crystal structure. This growth of 2D crystals into the third dimension presented a fascinating opportunity.
“You can engineer how much strain you impart to a crystal by designing objects for them to grow over,” said Kai Xiao, who with ORNL colleagues David Geohegan and postdoctoral researcher Kai Wang (now at Intel) conceived the study. “Strain is one way to make ‘hot spots’ for single photon emitters.”
Conformal growth of perfect 2D crystals over 3D objects has the promise to localize strain to create high-fidelity arrays of single photon emitters. Stretching or compressing the crystal lattice changes the material’s band gap, the energy gap between the valence and conduction bands of electrons, which largely determines a material’s optoelectronic properties. Using strain engineering, researchers can funnel charge carriers to recombine precisely where desired in the crystal instead of at random defect locations. By tailoring curved objects to localize strain in the crystal, and then measuring resulting shifts in optical properties, the experimentalists compelled co-authors at Rice University—theorists Henry Yu, Nitant Gupta and Boris Yakobson—to simulate and map how curvature induces strain during crystal growth.
At ORNL, Wang and Xiao designed experiments with Bernadeta Srijanto to explore the growth of 2D crystals over lithographically patterned arrays of nanoscale shapes. Srijanto first used photolithography masks to protect certain areas of a silicon oxide surface during exposure to light, and then etched away the exposed surfaces to leave vertically standing shapes, including donuts, cones and steps. Wang and another postdoctoral researcher, Xufan Li (now at Honda Research Institute), then inserted the substrates into a furnace where vaporized tungsten oxide and sulfur reacted to deposit tungsten disulfide on the substrates as monolayer crystals. The crystals grew as an orderly lattice of atoms in perfect triangular tiles that grew larger with time by adding row after row of atoms to their outer edges. While the 2D crystals seemed to effortlessly fold like paper over tall steps and sharp trenches, growth over curved objects forced the crystals to stretch to maintain their triangular shape.
The scientists found that “donuts” 40 nanometers high were great candidates for single photon emitters because the crystals could reliably tolerate the strain they induced, and the maximum strain was precisely in the “hole” of the donut, as measured by shifts in the photoluminescence and Raman scattering. In the future, arrays of donuts or other structures could be patterned anywhere that quantum emitters are desired before the crystals are grown.
Wang and ORNL co-author Alex Puretzky used photoluminescence mapping to reveal where the crystals nucleated and how fast each edge of the triangular crystal progressed as it grew over the donuts. After careful analysis of the images, they were surprised to discover that although the crystals maintained their perfect shapes, the edges of crystals that had been strained by donuts grew faster.
To explain this acceleration, Puretzky developed a crystal growth model, and colleague Mina Yoon conducted first-principles calculations. Their work showed that strain is more likely to induce defects on the growing edge of a crystal. These defects can multiply the number of nucleation sites that seed crystal growth along an edge, allowing it to grow faster than before.
The reason crystals can grow easily up and down deep trenches, but become strained by shallow donuts, has to do with conformity and curvature. Imagine wrapping presents. Boxes are easy to wrap because the paper can fold to conform to the shape. But an irregularly shaped object with curves, such as an unboxed mug, is impossible to wrap conformally (to avoid tearing the paper, you would have to be able to stretch it like plastic wrap.)
The 2D crystals also stretch to conform to the substrate’s curves. Eventually, however, the strain becomes too great and the crystals split to release the strain, atomic force microscopy and other techniques revealed. After the crystal cracks, growth of the still-strained material proceeds in different directions for each new arm. At Nanjing University of Aeronautics and Astronautics, Zhili Hu performed phase-field simulations of crystal branching. Xiang Gao of ORNL and Mengkun Tian (formerly of the University of Tennessee) analyzed the atomic structure of the crystals by scanning transmission electron microscopy.
“The results present exciting opportunities to take two-dimensional materials and vertically integrate them into the third dimension for next-generation electronics,” said Xiao.
Next the researchers will explore whether strain can enhance the performance of tailored materials. “We’re exploring how the strain of the crystal can make it easier to induce a phase change so the crystal can take on entirely new properties,” Xiao said. “At the Center for Nanophase Materials Sciences, we’re developing tools that will allow us to probe these structures and their quantum information aspects.”
The title of the paper is “Strain tolerance of two-dimensional crystal growth on curved surfaces.”
The DOE Office of Science supported material growth and structural and optical characterizations, which were performed at the Center for Nanophase Materials Sciences, a DOE Office of Science User Facility. This research also used resources of the National Energy Research Scientific Computing Center, also a DOE Office of Science User Facility. Work at Rice was supported by an Office of Naval Research grant.
UT-Battelle manages ORNL for DOE’s Office of Science. The single largest supporter of basic research in the physical sciences in the United States, the Office of Science is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science. —by Dawn Levy

MORE NEWS FROM
Oak Ridge National LaboratoryParticipating Labs
- DOE Office of Science
- Argonne National Laboratory
- Oak Ridge National Laboratory
- Pacific Northwest National Laboratory
- Iowa State University, Ames Laboratory
- Brookhaven National Laboratory
- Princeton Plasma Physics Laboratory
- Lawrence Berkeley National Laboratory
- Thomas Jefferson National Accelerator Facility
- Fermi National Accelerator Laboratory (Fermilab)
- SLAC National Accelerator Laboratory

Batten down the hatches: Preventing heat leaks to help create a star on Earth
PPPL physicists have identified a method by which instabilities can be tamed and heat can be prevented from leaking from fusion plasma, giving scientists a better grasp on how to optimize conditions for fusion in devices known as tokamaks.

Quenching Water Scarcity with a Good Pore
Researchers at UC San Diego and MIT linked theory and experiment to move closer to developing materials that address global water scarcity.

Simulations Attempt to Reconstruct One of the Most Explosive Events in the Universe: A Neutron Star Merger
A team led by scientists that included Berkeley Lab researchers has simulated the formation of a disc of matter, a giant burst of ejected matter, and the startup of energetic jets in the aftermath of a merger by two neutron stars.

Tiny Quantum Sensors Watch Materials Transform Under Pressure
Scientists at Berkeley Lab have developed a diamond anvil sensor that could lead to a new generation of smart, designer materials, as well as the synthesis of new chemical compounds, atomically fine-tuned by pressure.

Scientists harvest energy from light using bio-inspired artificial cells
By replicating biological machinery with non-biological components, scientists have created artificial cells that convert light into chemical energy.

Argonne's debt to 2019 Nobel Prize for lithium-ion battery
A roar of approval rang out at the U.S. Department of Energy's (DOE's) Argonne National Laboratory upon the announcement in October that John B. Goodenough, M. Stanley Whittingham and Akira Yoshino had won the 2019 Nobel Prize in Chemistry. On December 10th in Stockholm, they received this highly coveted prize for their major contributions to the invention of the lithium-ion battery, which is a long-standing major focus of research at Argonne.

Battery collaboration meeting discusses new pathways to recycle lithium-ion batteries
At a conference held by the ReCell Center, an advanced battery recycling collaboration based at Argonne, representatives from industry, government, and academia discussed innovative approaches for lithium-ion battery recycling.

New Function for Plant Enzyme Could Lead to Green Chemistry
Scientists at Brookhaven National Laboratory have discovered a new function in a plant enzyme that could inspire the design of new chemical catalysts. The enzyme catalyzes, or initiates, one of the cornerstone chemical reactions needed to synthesize a wide array of organic molecules, including those found in lubricants, cosmetics, and those used as raw materials for making plastics.

Freeze Frame: Scientists Capture Atomic-Scale Snapshots of Artificial Proteins
Scientists at Berkeley Lab are the first to use cryo-EM (cryogenic electron microscopy), a Nobel Prize-winning technique originally designed to image proteins in solution, to image atomic changes in a synthetic soft material.

Argonne Collaboration Shows Benefits of Better Corn Residue Management Strategies
Sustainable corn stover removal can maintain soil carbon stock, according a new Argonne-led study.

James Wilson Clark, PPPL's first deputy director for administrative operations, was a decorated World War II veteran, experienced federal administrator, and active member of the Princeton community
James W. Clark, PPPL's first deputy director for administrative operations, was a decorated World War II veteran with a long career in public service, who died Aug. 6. A memorial service in his honor will be held Dec. 21.
Department of Energy to Provide $24 Million in EPSCoR Grants for Energy-Related Research
The U.S. Department of Energy (DOE) announced a funding opportunity for up to $24 million for new grants under the Established Program to Stimulate Competitive Research (DOE EPSCoR).

University of Kentucky Grant Seeks to Turn Coal Into Carbon Fiber
UK's Center for Applied Energy Research (CAER) has received a $1.8 million U.S. Department of Energy (DOE) grant to transform coal tar pitch into high-value carbon fiber for use in aircraft, automobiles, sporting goods and other high-performance materials.

Six Berkeley Lab Scientists Named AAAS Fellows
Six scientists from the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have been named Fellows of the American Association for the Advancement of Science (AAAS).

PPPL is recognized for being green
The U.S. Department of Energy's Princeton Plasma Physics Laboratory was recognized by the U.S. Environmental Protection Agency for its green practices in reducing waste, energy, and water, and transportation, and for green purchasing and electronics recycling.

Dmitri Zakharov Recognized with the 2019 Chuck Fiori Award
The award honors Dmitri Zakharov's contributions to environmental transmission electron microscopy at Brookhaven Lab's Center for Functional Nanomaterials.

Two Argonne projects earn Secretary of Energy Honor Awards
With this year's Nobel Prize in Chemistry awarded for the development of lithium-ion batteries, directors of the Joint Center for Energy Storage Research share perspectives on the future of energy storage.

Argonne teams up with Altair to manage use of upcoming Aurora supercomputer
Argonne National Laboratory and Altair, a global technology company, have created a new scheduling system that will be employed on the Aurora supercomputer.

University of Maryland, Baltimore County wins DOE's 2019 CyberForce Competition(tm)
After a long suspenseful day, University of Maryland, Baltimore County earned the top spot as national winner of the U.S. Department of Energy's CyberForce Competition.

In its 15th year, INCITE advances open science with supercomputer grants to 47 projects
The U.S. Department of Energy's Office of Science announced allocations of supercomputer access to 47 science projects for 2020--awarding 60 percent of the available time on some of the nation's most powerful supercomputers, with the ultimate goal of accelerating discovery and innovation. In 2020, 14 projects will run on Theta and 39 projects on Summit, where six of these projects will receive an allocation on both systems.

Harvesting Energy from Light using Bio-inspired Artificial Cells
Scientists designed and connected two different artificial cells to each other to produce molecules called ATP (adenosine triphosphate).

Engineering Living Scaffolds for Building Materials
Bone and mollusk shells are composite systems that combine living cells and inorganic components. This allows them to regenerate and change structure while also being very strong and durable. Borrowing from this amazing complexity, researchers have been exploring a new class of materials called engineered living materials (ELMs).

Excavating Quantum Information Buried in Noise
Researchers developed two new methods to assess and remove error in how scientists measure quantum systems. By reducing quantum "noise" - uncertainty inherent to quantum processes - these new methods improve accuracy and precision.

How Electrons Move in a Catastrophe
Lanthanum strontium manganite (LSMO) is a widely applicable material, from magnetic tunnel junctions to solid oxide fuel cells. However, when it gets thin, its behavior changes for the worse. The reason why was not known. Now, using two theoretical methods, a team determined what happens.

When Ions and Molecules Cluster
How an ion behaves when isolated within an analytical instrument can differ from how it behaves in the environment. Now, Xue-Bin Wang at Pacific Northwest National Laboratory devised a way to bring ions and molecules together in clusters to better discover their properties and predict their behavior.

Tune in to Tetrahedral Superstructures
Shape affects how the particles fit together and, in turn, the resulting material. For the first time, a team observed the self-assembly of nanoparticles with tetrahedral shapes.

Tracing Interstellar Dust Back to the Solar System's Formation
This study is the first to confirm dust particles pre-dating the formation of our solar system. Further study of these materials will enable a deeper understanding of the processes that formed and have since altered them.

Investigating Materials that Can Go the Distance in Fusion Reactors
Future fusion reactors will require materials that can withstand extreme operating conditions, including being bombarded by high-energy neutrons at high temperatures. Scientists recently irradiated titanium diboride (TiB2) in the High Flux Isotope Reactor (HFIR) to better understand the effects of fusion neutrons on performance.

Better 3-D Imaging of Tumors in the Breast with Less Radiation
In breast cancer screening, an imaging technique based on nuclear medicine is currently being used as a successful secondary screening tool alongside mammography to improve the accuracy of the diagnosis. Now, a team is hoping to improve this imaging technique.

Microbes are Metabolic Specialists
Scientists can use genetic information to measure if microbes in the environment can perform specific ecological roles. Researchers recently analyzed the genomes of over 6,000 microbial species.
Spotlight

Barbara Garcia: A first-generation college student spends summer doing research at PPPL
Princeton Plasma Physics Laboratory

Argonne organization's scholarship fund blazes STEM pathway
Argonne National Laboratory

Brookhaven Lab, Suffolk Girl Scouts Launch Patch Program
Brookhaven National Laboratory

From an acoustic levitator to a "Neutron Bloodhound" robot, hands-on research inspires PPPL's summer interns
Princeton Plasma Physics Laboratory

Brookhaven Lab Celebrates the Bright Future of its 2019 Interns
Brookhaven National Laboratory

PPPL apprenticeship program offers young people chance to earn while they learn high-tech careers
Princeton Plasma Physics Laboratory

JSA Awards Graduate Fellowships for Research at Jefferson Lab
Thomas Jefferson National Accelerator Facility

ILSAMP Symposium showcases benefits for diverse students, STEM pipeline
Argonne National Laboratory

Integrating Scientific Computing into Science Curricula
Brookhaven National Laboratory
Students from Minnesota and Massachusetts Win DOE's 29th National Science Bowl(r)
Department of Energy, Office of Science
DOE's Science Graduate Student Research Program Selects 70 Students to Pursue Research at DOE Laboratories
Department of Energy, Office of Science

Young Women's Conference in STEM seeks to change the statistics one girl at a time
Princeton Plasma Physics Laboratory

Students team with Argonne scientists and engineers to learn about STEM careers
Argonne National Laboratory

Lynbrook High wins 2019 SLAC Regional Science Bowl competition
SLAC National Accelerator Laboratory

Equipping the next generation for a technological revolution
Argonne National Laboratory

Chemistry intern inspired by Argonne's real-world science
Argonne National Laboratory

Argonne intern streamlines the beamline
Argonne National Laboratory

Research on Light-Matter Interaction Could Lead to Improved Electronic and Optoelectronic Devices
Rensselaer Polytechnic Institute (RPI)

Innovating Our Energy Future
Oregon State University, College of Engineering

Physics graduate student takes her thesis research to a Department of Energy national lab
University of Alabama at Birmingham

"Model" students enjoy Argonne campus life
Argonne National Laboratory

Writing Code for a More Skilled and Diverse STEM Workforce
Brookhaven National Laboratory

New graduate student summer school launches at Princeton Plasma Physics Laboratory
Princeton Plasma Physics Laboratory

The Gridlock State
California State University (CSU) Chancellor's Office

Meet Jasmine Hatcher and Trishelle Copeland-Johnson
Brookhaven National Laboratory

Argonne hosts Modeling, Experimentation and Validation Summer School
Argonne National Laboratory

Undergraduate Students Extoll Benefits of National Laboratory Research Internships in Fusion and Plasma Science
Princeton Plasma Physics Laboratory

Students affected by Hurricane Maria bring their research to SLAC
SLAC National Accelerator Laboratory

Brookhaven Lab Pays Tribute to 2018 Summer Interns
Brookhaven National Laboratory

CSUMB Selected to Host Architecture at Zero Competition in 2019
California State University, Monterey Bay

From Hurricane Katrina Victim to Presidential Awardee: A SUNO Professor's Award-Winning Mentoring Efforts
Brookhaven National Laboratory

Department of Energy Invests $64 Million in Advanced Nuclear Technology
Rensselaer Polytechnic Institute (RPI)

Professor Miao Yu Named the Priti and Mukesh Chatter '82 Career Development Professor
Rensselaer Polytechnic Institute (RPI)

2018 RHIC & AGS Annual Users' Meeting: 'Illuminating the QCD Landscape'
Brookhaven National Laboratory

High-School Students Studying Carbon-Based Nanomaterials for Cancer Drug Delivery Visit Brookhaven Lab's Nanocenter
Brookhaven National Laboratory

Argonne welcomes The Martian author Andy Weir
Argonne National Laboratory

UW Professor and Clean Energy Institute Director Daniel Schwartz Wins Highest U.S. Award for STEM Mentors
University of Washington

Creating STEM Knowledge and Innovations to Solve Global Issues Like Water, Food, and Energy
Illinois Mathematics and Science Academy (IMSA)

Professor Emily Liu Receives $1.8 Million DoE Award for Solar Power Systems Research
Rensselaer Polytechnic Institute (RPI)

Celebrating 40 years of empowerment in science
Argonne National Laboratory

Introducing Graduate Students Across the Globe to Photon Science
Brookhaven National Laboratory

Students from Massachusetts and Washington Win DOE's 28th National Science Bowl(r)
Department of Energy, Office of Science

Q&A: Al Ashley Reflects on His Efforts to Diversify SLAC and Beyond
SLAC National Accelerator Laboratory

Insights on Innovation in Energy, Humanitarian Aid Highlight UVA Darden's Net Impact Week
University of Virginia Darden School of Business

Ivy League Graduate, Writer and Activist with Dyslexia Visits CSUCI to Reframe the Concept of Learning Disabilities
California State University, Channel Islands

Photographer Adam Nadel Selected as Fermilab's New Artist-in-Residence for 2018
Fermi National Accelerator Laboratory (Fermilab)
Showing results
0-4 Of 2215