The energy levels of electrons in a solid crystal lattice determine whether or not they can produce light, for example as light emitting diodes (LEDs).
An international team of scientists led by Oldenburg University Physicists Dr Hangyong Shan and Professor Christian Schneider have succeeded in synthesizing this material, which usually has a low gloss yield, so that it can glow – and have succeeded in changing the energy levels in samples of ultra-thin tungsten semiconductor materials.
The team publishes research papers in scientific journals Nature Communication.
The researchers claim that their findings are the first step in manipulating the physical properties of materials using light fields.
The idea has been discussed for years, but has not been conclusively implemented.
Christian Schneider, Physicist, University of Oldenburg
The light effect has the potential to enhance the optical capabilities of semiconductors, and as such will assist in the manufacture of advanced LEDs, solar cells, optical components, and other applications.
It can improve the optical quality of organic semiconductors or plastics with semiconductor properties used in multipurpose screens, solar cells, or as sensors in textiles.
An uncommon class of semiconductors consisting of a transition metal plus one of three elements – sulfur, selenium or tellurium – includes tungsten diselenide. The scientists used samples made of single-crystal layers of tungsten and selenium atoms in a sandwich form for their study.
Some of these thicker materials are also referred to as two-dimensional (2D) materials in physics. They are also referred to as “quantum materials”, because they often have the special feature of having the charge carriers they carry behave very differently from thicker solids.
The tungsten dislenide sample was placed between two specially designed mirrors designed by the researchers, guided by Shan and Schneider, and excited by a laser. They were able to pair energetic electrons and light particles (photons) using this technique.
“In our study, we show that through this coupling, electronic transition structures can be rearranged so that dark matter effectively behaves like light matter.Descripti Schneider. “The effect in our experiment is so strong that the lower state of tungsten diselenide becomes optically active. “
The researchers were also able to show that the experimental results accurately reflected a highly theoretical model.
The results are the result of a collaboration between scientists at Karl von Ossetsky University in Oldenburg (Germany) and colleagues from the University of Reykjavik (Iceland), the University of Würzburg (Germany), Friedrich Schiller University (Germany), and Arizona State University (USA). ) and the National Institute of Materials Science in Tsukuba (Japan). Part of the theory was developed by colleagues at the ITMO University in Saint Petersburg (Russia) before the universities ended their collaboration.
Journal reference:
Chan, H.; and others. (2022) Illumination of a dark monolayer semiconductor with strong coupling of light material in the cavity. Natural Connection. doi.org/10.1038/s41467-022-30645-5.
source: https://uol.de/ar
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