Towards better LED lighting

Designing energy efficient, high output, perfectly tinted LEDs

SASKATOON – Scientists have combined experimental data gathered at the Canadian Light Source at the University of Saskatchewan and theoretical data to build deep insight into two types of light emitting crystals for next-generation LEDs.

“When we have means of creating more efficient lighting, this has a huge environmental impact,” says Alexander Moewes, Canada Research Chair in Materials Science with Synchrotron Radiation at the University of Saskatchewan, who cites that lighting accounts for 15-20% of global electricity consumption, and therefore for roughly 5% of worldwide greenhouse gas emissions.

Read more on the CLS website

Image: Tristan de Boer,  Patrick Braun, Ruhul Amin, Alexander Moewes and Amir Qamar outside the Physics building at USask

Creating the best TV screen yet

Breakthrough in blue quantum dot technology

There are many things quantum dots could do, but the most obvious place they could change our lives is to make the colours on our TVs and screens more pristine. Research using the Canadian Light Source (CLS) at the University of Saskatchewan is helping to bring this technology closer to our living rooms.

Quantum dots are nanocrystals that glow, a property that scientists have been working with to develop next-generation LEDs. When a quantum dot glows, it creates very pure light in a precise wavelength of red, blue or green. Conventional LEDs, found in our TV screens today, produce white light that is filtered to achieve desired colours, a process that leads to less bright and muddier colours.

Until now, blue-glowing quantum dots, which are crucial for creating a full range of colour, have proved particularly challenging for researchers to develop. However, University of Toronto (U of T) researcher Dr. Yitong Dong and collaborators have made a huge leap in blue quantum dot fluorescence, results they recently published in Nature Nanotechnology.

Read more on the Canadian Light Source website

Image: The blue quantum dot solution glows in a vial in a laboratory.

Atomic Flaws Create Surprising, High-Efficiency UV LED Materials

Subtle surface defects increase UV light emission in greener, more cost-effective LED and catalyst materials

Light-emitting diodes (LEDs) traditionally demand atomic perfection to optimize efficiency. On the nanoscale, where structures span just billionths of a meter, defects should be avoided at all costs—until now.

A team of scientists from the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and Stony Brook University has discovered that subtle imperfections can dramatically increase the efficiency and ultraviolet (UV) light output of certain LED materials.

“The results are surprising and completely counterintuitive,” said Brookhaven Lab scientist Mingzhao Liu, the senior author on the study. “These almost imperceptible flaws, which turned out to be missing oxygen in the surface of zinc oxide nanowires, actually enhance performance. This revelation may inspire new nanomaterial designs far beyond LEDs that would otherwise have been reflexively dismissed.”

>Read more on the NSLS-II website

Image: The research team, front to back and left to right: Danhua Yan, Mingzhao Liu, Klaus Attenkoffer, Jiajie Cen, Dario Stacciola, Wenrui Zhang, Jerzy Sadowski, Eli Stavitski.