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Primeur weekly 2018-02-26

Focus

The European Processor Initiative (EPI) to develop the processor that will be at the heart of the European exascale supercomputer effort ...

Quantum computing

Unconventional superconductor may be used to create quantum computers of the future ...

Developing reliable quantum computers: International research team makes important step on the path to solving certification problems ...

Programming on a silicon quantum chip ...

D-Wave locks in $20 million funding and completes prototype of next-gen quantum processor ...

Focus on Europe

Luxembourg joins the European supercomputer network PRACE ...

ICEI Public Information Event on the realisation of a federated HPC and data analytics infrastructure ...

Dutch eScience and Lorentz Centers launch Call to host workshop on digitally enhanced research ...

Middleware

Adaptive Computing announces release of Moab HPC Suite 9.1.2 ...

NCSA Assistant Director Dan Katz named BSSw Fellow ...

University of Nevada, Las Vegas' supercomputing boosted through new collaboration with Altair ...

Hardware

C-DAC focusing on cancer treatment using supercomputers as a tool ...

South-Korean Ministry of Science and Technology to announce Second National High-Performance Computing Fundamental Plan ...

IBM reveals novel energy-saving optical receiver with a new record of rapid power-on/off time ...

Computers learn to learn: Intel and researchers from Heidelberg and Dresden present three new neuromorphic chips ...

HPE helps U.S. Department of Defense to advance national defense capabilities ...

OCF deploys petascale Lenovo supercomputer at University of Southampton ...

HPE reports fiscal 2018 first quarter results ...

Ranovus announces general availability of its on-board optics and CFP2 direct detect transceiver products for 5G mobility and data centre interconnect applications ...

Mellanox appoints Steve Sanghi and Umesh Padval to Board of Directors ...

Applications

Supercomputers aid discovery of new, inexpensive material to make LEDs with high colour quality ...

AI companies to reuse crypto mining farms for deep learning in health care ...

Computer scientists and materials researchers collaborate to optimize steel classification ...

Boris Kaus receives ERC Consolidator Grant for his research in magmatic processes ...

Metabolic modelling becomes three-dimensional ...

Powerful supercomputer unlocks possibilities for tinier devices and affordable DNA sequencing ...

New Berkeley Lab algorithms create "Minimalist Machine Learning" that analyzes images from very little information ...

The Cloud

Adaptive Computing makes HPC Cloud strategies more accessible with the Moab/NODUS Cloud Bursting 1.1.0 release ...

USFlash

Gen-Z Consortium announces the public release of its Core Specification 1.0 ...

Supercomputers aid discovery of new, inexpensive material to make LEDs with high colour quality


Untouched shots lit by (left) an LED containing a conventional phosphor and (right) a prototype LED containing the new SLAO phosphor. Image courtesy of Yoon Hwa Kim and Wong Bin Im/Chonnam National University in Korea.
19 Feb 2018 San Diego - A team led by engineers at the University of California San Diego has used data mining and computational tools to discover a new phosphor material for white LEDs that is inexpensive and easy to make. Researchers built prototype white LED light bulbs using the new phosphor. The prototypes exhibited better color quality than many commercial LEDs currently on the market.

Researchers published the new phosphor on February 19 in the journalJoule.

Phosphors, which are substances that emit light, are one of the key ingredients to make white LEDs. They are crystalline powders that absorb energy from blue or near-UV light and emit light in the visible spectrum. The combination of the different colored light creates white light.

The phosphors used in many commercial white LEDs have several disadvantages, however. Many are made of rare-earth elements, which are expensive, and some are difficult to manufacture. They also produce LEDs with poor colour quality.

Researchers at UC San Diego and Chonnam National University in Korea discovered and developed a new phosphor that avoids these issues. It is made mostly of earth-abundant elements; it can be made using industrial methods; and it produces LEDs that render colors more vividly and accurately.

The new phosphor - made of the elements strontium, lithium, aluminum and oxygen (a combination dubbed "SLAO") - was discovered using a systematic, high-throughput computational approach developed in the lab of Shyue Ping Ong, a nano-engineering professor at the UC San Diego Jacobs School of Engineering and lead principal investigator of the study. Shyue Ping Ong's team used supercomputers to predict SLAO, which is the first known material made of the elements strontium, lithium, aluminum and oxygen. Calculations also predicted this material would be stable and perform well as an LED phosphor. For example, it was predicted to absorb light in the near-UV and blue region and have high photoluminescence, which is the material's ability to emit light when excited by a higher energy light source.

Researchers in the lab of Joanna McKittrick, a materials science professor at the Jacobs School of Engineering, then figured out the recipe needed to make the new phosphor. They also confirmed the phosphor's predicted light absorption and emission properties in the lab.

A team led by materials science professor Won Bin Im at Chonnam National University in Korea optimized the phosphor recipe for industrial manufacturing and built white LED prototypes with the new phosphor. They evaluated the LEDs using the Color Rendering Index (CRI), a scale that rates from 0 to 100 how accurate colours appear under a light source. Many commercial LEDs have CRI values at around 80. LEDs made with the new phosphor yielded CRI values greater than 90.

Thanks to the computational approach developed by Shyue Ping Ong's team, discovery of the phosphor took just three months - a short time frame compared to the years of trial-and-error experiments it typically takes to discover a new material.

"Calculations are quick, scalable and cheap. Using computers, we can rapidly screen thousands of materials and predict candidates for new materials that have not yet been discovered", Shyue Ping Ong stated.

Shyue Ping Ong, who leads the Materials Virtual Lab and is a faculty member in the Sustainable Power and Energy Center at UC San Diego, uses a combination of high-throughput calculations and machine learning to discover next-generation materials for energy applications, including batteries, fuel cells and LEDs. The calculations were performed using the National Science Foundation's Extreme Science and Engineering Discovery Environment at the San Diego Supercomputer Center.

In this study, Shyue Ping Ong's team first compiled a list of the most frequently occurring elements in known phosphor materials. To the researchers' surprise, they found that there are no known materials containing a combination of strontium, lithium, aluminum and oxygen, which are four common phosphor elements. Using a data mining algorithm, they created new phosphor candidates containing these elements and performed a series of first-principles calculations to predict which would perform well as a phosphor. Out of 918 candidates, SLAO emerged as the leading material. It was predicted to be stable and exhibit excellent photoluminescence properties.

"It's not only remarkable that we were able to predict a new phosphor compound, but one that's stable and can actually be synthesized in the lab", stated Zhenbin Wang, a nanoengineering Ph.D. candidate in Shyue Ping Ong's research group and co-first author of the study.

The phosphor's main limitation is its less than ideal quantum efficiency - how efficiently it converts incoming light to light of a different colour - of about 32 percent. However, researchers note that it retains more than 88 percent of its emission at typical LED operating temperatures. In commercial LEDs, there's usually a trade-off with colour quality, Shyue Ping Ong noted. "But we want the best of both worlds. We have achieved excellent colour quality. Now we are working on optimizing the material to improve quantum efficiency", Shyue Ping Ong stated.

The paper is titled "Mining Unexplored Chemistries for Phosphors for High-Color-Quality White-Light-Emitting Diodes". Authors of the study are Zhenbin Wang, Jungmin Ha, Joanna McKittrick and Shyue Ping Ong at UC San Diego; and Yoon Hwa Kim and Won Bin Im at Chonnam National University, Republic of Korea.

This work was supported by the National Science Foundation, Ceramics Programme (grant 1411192). Computational resources were provided by the Triton Shared Computing Cluster at UC San Diego, the National Energy Research Scientific Computing Centre, and the Extreme Science and Engineering Discovery Environment supported by the National Science Foundation (grant ACI-1053575). This work was also supported by the Basic Science Research Programme through the National Research Foundation of Korea, which is funded by the Ministry of Science and ICT (NRF-2017R1A2B3011967).
Source: University of California - San Diego

Back to Table of contents

Primeur weekly 2018-02-26

Focus

The European Processor Initiative (EPI) to develop the processor that will be at the heart of the European exascale supercomputer effort ...

Quantum computing

Unconventional superconductor may be used to create quantum computers of the future ...

Developing reliable quantum computers: International research team makes important step on the path to solving certification problems ...

Programming on a silicon quantum chip ...

D-Wave locks in $20 million funding and completes prototype of next-gen quantum processor ...

Focus on Europe

Luxembourg joins the European supercomputer network PRACE ...

ICEI Public Information Event on the realisation of a federated HPC and data analytics infrastructure ...

Dutch eScience and Lorentz Centers launch Call to host workshop on digitally enhanced research ...

Middleware

Adaptive Computing announces release of Moab HPC Suite 9.1.2 ...

NCSA Assistant Director Dan Katz named BSSw Fellow ...

University of Nevada, Las Vegas' supercomputing boosted through new collaboration with Altair ...

Hardware

C-DAC focusing on cancer treatment using supercomputers as a tool ...

South-Korean Ministry of Science and Technology to announce Second National High-Performance Computing Fundamental Plan ...

IBM reveals novel energy-saving optical receiver with a new record of rapid power-on/off time ...

Computers learn to learn: Intel and researchers from Heidelberg and Dresden present three new neuromorphic chips ...

HPE helps U.S. Department of Defense to advance national defense capabilities ...

OCF deploys petascale Lenovo supercomputer at University of Southampton ...

HPE reports fiscal 2018 first quarter results ...

Ranovus announces general availability of its on-board optics and CFP2 direct detect transceiver products for 5G mobility and data centre interconnect applications ...

Mellanox appoints Steve Sanghi and Umesh Padval to Board of Directors ...

Applications

Supercomputers aid discovery of new, inexpensive material to make LEDs with high colour quality ...

AI companies to reuse crypto mining farms for deep learning in health care ...

Computer scientists and materials researchers collaborate to optimize steel classification ...

Boris Kaus receives ERC Consolidator Grant for his research in magmatic processes ...

Metabolic modelling becomes three-dimensional ...

Powerful supercomputer unlocks possibilities for tinier devices and affordable DNA sequencing ...

New Berkeley Lab algorithms create "Minimalist Machine Learning" that analyzes images from very little information ...

The Cloud

Adaptive Computing makes HPC Cloud strategies more accessible with the Moab/NODUS Cloud Bursting 1.1.0 release ...

USFlash

Gen-Z Consortium announces the public release of its Core Specification 1.0 ...