Nav: Home

Exotic spiraling electrons discovered by physicists

February 18, 2019

Rutgers and other physicists have discovered an exotic form of electrons that spin like planets and could lead to advances in lighting, solar cells, lasers and electronic displays.

It's called a "chiral surface exciton," and it consists of particles and anti-particles bound together and swirling around each other on the surface of solids, according to a study in the Proceedings of the National Academy of Sciences.

Chiral refers to entities, like your right and left hands, that match but are asymmetrical and can't be superimposed on their mirror image.

Excitons form when intense light shines on solids, kicking negatively charged electrons out of their spots and leaving behind positively charged "holes," according to lead author Hsiang-Hsi (Sean) Kung, a graduate student in Physics Professor Girsh Blumberg's Rutgers Laser Spectroscopy Lab at Rutgers University-New Brunswick.

The electrons and holes resemble rapidly spinning tops. The electrons eventually "spiral" towards the holes, annihilating each other in less than a trillionth of a second while emitting a kind of light called "photoluminescence." This finding has applications for devices such as solar cells, lasers and TV and other displays.

The scientists discovered chiral excitons on the surface of a crystal known as bismuth selenide, which could be mass-produced and used in coatings and other materials in electronics at room temperature.

"Bismuth selenide is a fascinating compound that belongs to a family of quantum materials called 'topological insulators,'" said senior author Blumberg, a professor in the Department of Physics and Astronomy in the School of Arts and Sciences. "They have several channels on the surface that are highly efficient in conducting electricity."

The dynamics of chiral excitons are not yet clear and the scientists want to use ultra-fast imaging to further study them. Chiral surface excitons may be found on other materials as well.
-end-
Rutgers co-authors include doctoral students Xueyun Wang and Alexander Lee, and Board of Governors Professor Sang-Wook Cheong in Rutgers Center for Emergent Materials, who developed the ultra-pure crystals for this study. Professor Dmitrii Maslov and graduate student Adamya Goyal at the University of Florida and principal investigator Alexander Kemper at North Carolina State University contributed to theory development and the interpretation of results.
-end-


Rutgers University

Related Solar Cells Articles:

Next gen solar cells perform better when there's a camera around
A literal ''trick of the light'' can detect imperfections in next-gen solar cells, boosting their efficiency to match that of existing silicon-based versions, researchers have found.
On the trail of organic solar cells' efficiency
Scientists at TU Dresden and Hasselt University in Belgium investigated the physical causes that limit the efficiency of novel solar cells based on organic molecular materials.
Exciting tweaks for organic solar cells
A molecular tweak has improved organic solar cell performance, bringing us closer to cheaper, efficient, and more easily manufactured photovoltaics.
For cheaper solar cells, thinner really is better
Researchers at MIT and at the National Renewable Energy Laboratory (NREL) have outlined a pathway to slashing costs further, this time by slimming down the silicon cells themselves.
Flexible thinking on silicon solar cells
Combining silicon with a highly elastic polymer backing produces solar cells that have record-breaking stretchability and high efficiency.
Perovskite solar cells get an upgrade
Rice University materials scientists find inorganic compounds quench defects in perovskite-based solar cells and expand their tolerance of light, humidity and heat.
Can solar technology kill cancer cells?
Michigan State University scientists have revealed a new way to detect and attack cancer cells using technology traditionally reserved for solar power.
Solar cells with new interfaces
Scientists from NUST MISIS (Russia) and University of Rome Tor Vergata found out that a microscopic quantity of two-dimensional titanium carbide called MXene significantly improves collection of electrical charges in a perovskite solar cell, increasing the final efficiency above 20%.
Welcome indoors, solar cells
Swedish and Chinese scientists have developed organic solar cells optimised to convert ambient indoor light to electricity.
Mapping the energetic landscape of solar cells
A new spectroscopic method now makes it possible to measure and visualize the energetic landscape inside solar cells based on organic materials.
More Solar Cells News and Solar Cells Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Biology Of Sex
Original broadcast date: May 8, 2020. Many of us were taught biological sex is a question of female or male, XX or XY ... but it's far more complicated. This hour, TED speakers explore what determines our sex. Guests on the show include artist Emily Quinn, journalist Molly Webster, neuroscientist Lisa Mosconi, and structural biologist Karissa Sanbonmatsu.
Now Playing: Science for the People

#569 Facing Fear
What do you fear? I mean really fear? Well, ok, maybe right now that's tough. We're living in a new age and definition of fear. But what do we do about it? Eva Holland has faced her fears, including trauma and phobia. She lived to tell the tale and write a book: "Nerve: Adventures in the Science of Fear".
Now Playing: Radiolab

The Wubi Effect
When we think of China today, we think of a technological superpower. From Huweai and 5G to TikTok and viral social media, China is stride for stride with the United States in the world of computing. However, China's technological renaissance almost didn't happen. And for one very basic reason: The Chinese language, with its 70,000 plus characters, couldn't fit on a keyboard.  Today, we tell the story of Professor Wang Yongmin, a hard headed computer programmer who solved this puzzle and laid the foundation for the China we know today. This episode was reported and produced by Simon Adler with reporting assistance from Yang Yang. Special thanks to Martin Howard. You can view his renowned collection of typewriters at: antiquetypewriters.com Support Radiolab today at Radiolab.org/donate.