Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Hybrid semiconductors show zero thermal expansion; could lead to hardier electronics and optoelectronics

The crystal structure of -ZnTe(en)0:5, determined by single-crystal X-ray diffraction. Two-monolayerthick ZnTe slabs are interconnected by ethylenediamine (C2N2H8) molecules bonded to zinc atoms. Zn-Green, Te-Red, N-Blue,and C-Gray. Hydrogen atoms are omitted for clarity.
The crystal structure of -ZnTe(en)0:5, determined by single-crystal X-ray diffraction. Two-monolayerthick ZnTe slabs are interconnected by ethylenediamine (C2N2H8) molecules bonded to zinc atoms. Zn-Green, Te-Red, N-Blue,and C-Gray. Hydrogen atoms are omitted for clarity.

Abstract:
The fan in your computer is there to keep the microprocessor chip from heating to the point where its component materials start to expand, inducing cracks that interrupt the flow of electricity — and not incidentally, ruin the chip. Thermal expansion can also separate semiconducting materials from the substrate, reduce performance through changes in the electronic structure of the material or warp the delicate structures that emit laser light.

Hybrid semiconductors show zero thermal expansion; could lead to hardier electronics and optoelectronics

ARGONNE, IL | Posted on December 19th, 2007

Recently published research by scientists at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) and Argonne National Laboratory, and academic institutions has shed light on a semiconducting material with zero thermal expansion (ZTE). The research may play a role in the design of future generations of electronics and optoelectronics that can withstand a wide range of temperatures.

Traditional interests in ZTE materials have largely been in areas such as optics, heat-engine components and kitchenware. ZTE materials with applications in non-conventional areas such as electronics and optoelectronics are rare; most are glasses, which do not work well in electronics applications. The hybrid inorganic-organic semiconductor investigated in this work is a multifunctional semiconductor that has previously been shown to possess superior electronic and optical properties. The work also suggests an alternative route to designing materials with any desired positive or negative thermal expansion.

"It's a merger of inorganic and organic materials," said Zahirul Islam, a physicist in Argonne's X-Ray Science Division, "which form a fully coherent, three-dimensionally ordered crystal. Normally inorganic and organic materials don't work very well together, but here they are working together to display these remarkable properties."

The materials under study form alternating organic and inorganic layers that work together to produce these effects. One contracts while the other expands, and the net effect is zero.

"This work suggests a novel approach to design the thermal expansion — from positive to negative, including zero — in a nanoscopic scale by assembling nano-scale units in an ordered manner," said principal investigator Yong Zhang of NREL. "The idea has only been demonstrated for tuning thermal expansion in one dimension and study was limited to one or two materials. Next, we would like to extend the idea to higher dimensions (i.e., ZTE in more than one dimension), and explore more inorganic-organic combinations."

These hybrid materials hold promise for high-efficiency semiconductor lasers, ultrathin and flexible solar cells and light-emitting and detecting devices. It is possible to "dope" the materials (adding small amounts of other compounds) to form transparent conducting materials, Zhang said.

While chemical and thermal stability are two major problems for most hybrids, the hybrid nanostructures investigated in this work are found to be exceptionally stable in the air, even under the illumination of an ultraviolet laser.

"Not only do the crystal structures remain unchanged," Zhang said, "but their electronic and optical properties remain after a few years of air exposure or upon heating to more than 200 degrees C, a feature attributed to the strong covalent bonding throughout the structure."

This work involved multiple institutes with complementary strengths and capabilities. Scientists at NREL initiated and organized the project. The materials were synthesized by Jing Li's group at Rutgers University. Critical X-ray diffraction measurements to determine the ZTE effects were carried out at Argonne's Advanced Photon Source. Other key Argonne researchers are Yang Ren and Peter L. Lee. Theoretical modeling on the phonon (vibrational) spectrum, crucial to the understanding of the experimental findings, was performed by scientists at the University of Arkansas. Collaborators at the University of Colorado at Boulder also made important contributions to the work.

####

About Argonne National Laboratory
Argonne National Laboratory, a renowned R&D center, brings the world's brightest scientists and engineers together to find exciting and creative new solutions to pressing national problems in science and technology. The nation's first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America 's scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.

By Dave Jacqué.

For more information, please click here

Contacts:
Steve McGregor
630/252-5580

at Argonne

Copyright © Argonne 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 News Press

News and information

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Promising results obtained with a new electrocatalyst that reduces the need for platinum: Researchers from Aalto University have succeeded in manufacturing electrocatalysts used for storing electric energy with one-hundredth of the amount of platinum that is usually needed March 24th, 2017

Leti Presents Advances in Propagation Modeling and Antenna Design for mmWave Spectrum: Paper Is One of 15 that Leti Presented at European Conference on Antennas and Propagation March 19-24 March 23rd, 2017

Rice U. refines filters for greener natural gas: New study defines best materials for carbon capture, methane selectivity March 23rd, 2017

Laboratories

Researchers develop groundbreaking process for creating ultra-selective separation membranes: Discovery could greatly improve energy-efficiency of separation and purification processes in the chemical and petrochemical industries March 15th, 2017

Discovery in new material raises questions about theoretical models of superconductivity March 13th, 2017

Perovskite edges can be tuned for optoelectronic performance: Layered 2D material improves efficiency for solar cells and LEDs March 10th, 2017

Imaging the inner workings of a sodium-metal sulfide battery for first time: Understanding how the structural and chemical makeup of the material changes during the charge/discharge process could help scientists advance battery design for future energy storage needs March 9th, 2017

Chip Technology

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Scientists discover new 'boat' form of promising semiconductor: GeSe Uncommon form attenuates semiconductor's band gap size March 23rd, 2017

Pulverizing e-waste is green, clean -- and cold: Rice, Indian Institute researchers use cryo-mill to turn circuit boards into separated powders March 21st, 2017

Electro-optical switch transmits data at record-low temperatures: Operating at temperatures near absolute zero, switch could enable significantly faster data processing with lower power consumption March 20th, 2017

Discoveries

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Promising results obtained with a new electrocatalyst that reduces the need for platinum: Researchers from Aalto University have succeeded in manufacturing electrocatalysts used for storing electric energy with one-hundredth of the amount of platinum that is usually needed March 24th, 2017

Rice U. refines filters for greener natural gas: New study defines best materials for carbon capture, methane selectivity March 23rd, 2017

Artificial photosynthesis steps into the light: Rice University lab turns transition metals into practical catalyst for solar, other applications March 23rd, 2017

Announcements

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Promising results obtained with a new electrocatalyst that reduces the need for platinum: Researchers from Aalto University have succeeded in manufacturing electrocatalysts used for storing electric energy with one-hundredth of the amount of platinum that is usually needed March 24th, 2017

Rice U. refines filters for greener natural gas: New study defines best materials for carbon capture, methane selectivity March 23rd, 2017

Artificial photosynthesis steps into the light: Rice University lab turns transition metals into practical catalyst for solar, other applications March 23rd, 2017

Alliances/Trade associations/Partnerships/Distributorships

AIM Photonics Welcomes Coventor as Newest Member: US-Backed Initiative Taps Process Modeling Specialist to Enable Manufacturing of High-Yield, High-Performance Integrated Photonic Designs March 16th, 2017

Applied Graphene Materials plc - Significant commercial progress in AGM’s three core sectors March 3rd, 2017

Strem Chemicals and Dotz Nano Ltd. Sign Distribution Agreement for Graphene Quantum Dots Collaboration February 21st, 2017

Leti Coordinating Project to Adapt Obstacle-Detection Technology Used in Autonomous Cars for Portable and Wearable Systems: INSPEX to Combine Knowhow of Nine European Organizations to Create Portable and Wearable Spatial-Exploration Systems February 2nd, 2017

Research partnerships

Argon is not the 'dope' for metallic hydrogen March 24th, 2017

Rice U. refines filters for greener natural gas: New study defines best materials for carbon capture, methane selectivity March 23rd, 2017

Artificial photosynthesis steps into the light: Rice University lab turns transition metals into practical catalyst for solar, other applications March 23rd, 2017

Pulverizing e-waste is green, clean -- and cold: Rice, Indian Institute researchers use cryo-mill to turn circuit boards into separated powders March 21st, 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