Close

Search

Search Menu
Photonics Media Photonics Marketplace Photonics Spectra BioPhotonics Vision Spectra Photonics Showcase Photonics ProdSpec Photonics Handbook
LightMachinery Inc. - Picometer resolution

Light-Matter Coupling Makes Dark Semiconductor Material Glow

Facebook Twitter LinkedIn Email
OLDENBURG, Germany, June 28, 2022 — Researchers from the University of Oldenburg have introduced a light-matter coupling mechanism to make the 2D semiconductor material tungsten diselenide (WSe2) glow — marking a step toward the control of the properties of matter through light fields. The scientists manipulated the energy levels in an ultrathin sample of the material, which normally possesses a low luminescence yield.

Physicists Hangyong Shan and Christian Schneider led the research. According to the team, the light effect could be used to optimize the optical properties of semiconductors. This level of optimization could then contribute to the development of innovative LEDs, solar cells, optical components, and more.

In particular, the researchers said, the materials solution could enhance the optical properties of organic semiconductors that are used in flexible displays and solar cells, as well as sensors in textiles.
In their experiments, University of Oldenburg physicists directed laser light onto samples of extremely thin semiconductors with various optical components. The experiments could serve to enhance enhance the optical properties of organic semiconductors that are used in flexible displays and solar cells, as well as sensors in textiles.Courtesy of the University of Oldenburg.
University of Oldenburg physicists directed laser light onto samples of extremely thin semiconductors with various optical components. The experiments could serve to enhance the optical properties of organic semiconductors that are used in flexible displays and solar cells, as well as sensors in textiles. Courtesy of the University of Oldenburg. 
The researchers placed a sample of WSe2 between two specially prepared mirrors and excited the material using a nonresonant continuous-wave laser at 532 nm. The sample consisted of a single crystalline layer of tungsten and selenium atoms with a sandwich-like structure.

The researchers used the method to create a coupling between photons and excited electrons. In a demonstration, they showed that the coupling enabled the structure of electronic transitions to be rearranged such that the dark material — WSe2 — effectively behaved like a bright one.

Whether a solid can emit light, such as an LED, depends on the energy levels of the electrons in the crystalline lattice of the solid. The researchers also pointed out that quantum 2D materials such as WSe2 often feature unusual properties because the charge carriers that they contain behave in a manner that is different than those in thicker solids.

According to Schneider, the effect of the experiment is so strong that the lower state of WSe2 becomes optically active as the experiment takes place.

Additionally, the team showed that its experimental results matched the predictions of a theoretical model to a high degree.

The current study is the result of a multi-institutional collaboration with researchers from institutions in Germany, Iceland, the U.S., and Japan.

The research was published in Nature Communications (www.doi.org/10.1038/s41467-022-30645-5).

Photonics.com
Jun 2022
Research & Technologyeducationlight sourceslight-matter interactionslight-matter couplingcouplingDisplaysmaterialssemiconductor materialsQuantum Materials2D materialsEuropeLEDssemiconductorstungsten diselenideUniversity of Oldenburg

back to top
Facebook Twitter Instagram LinkedIn YouTube RSS
©2022 Photonics Media, 100 West St., Pittsfield, MA, 01201 USA, [email protected]

Photonics Media, Laurin Publishing
x We deliver – right to your inbox. Subscribe FREE to our newsletters.
We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.