What did scientists discover?
A new class of atomically-thin semiconductors known as the transition metal dichalcogenides was recently discovered, and scientists working at the MagLab have revealed several of their fundamental optical and electronic properties using a combination of optical spectroscopy and high magnetic fields.
Why is this important?
Semiconductors play the key role in many technological opto-electronic applications, including lasers, light-emitting diodes, and solar cells. Being atomically-thin, these new 2D materials have the potential to miniaturize and improve upon many existing technologies. It is essential to measure and understand the essential optical and electronic properties exhibited by this new material class, so that future devices can be designed.
Who did the research?
Andreas V. Stier1, Kathleen M. McCreary2, Berend T. Jonker2, Junichiro Kono3, Scott A. Crooker1
1NHMFL-Los Alamos National Laboratory; 2Naval Research Laboratory; 3Rice University
Why did they need the MagLab?
THE TOOLS THEY USED
This research was conducted in the 65 Tesla Multi-Shot Magnet at the MagLab's Pulsed Field Facility located at Los Alamos.
The tiny energy shifts of the laser-induced excitations can only be clearly observed in extremely large magnetic fields. Unlike conventional semiconductors, such as silicon and gallium arsenide, the electrons in these new two-dimensional materials are very tightly bound together and behave as though they are very heavy. Practically, this means that very large magnetic fields exceeding 50 tesla are required to probe their properties. These experiments were made possible by the combination of the MagLab's 65 tesla pulsed magnets and the MagLab's laser and optical instrumentation infrastructure.
Details for scientists
- View or download the expert-level Science Highlight,
Optical Spectroscopy of New Atomically-Thin Semiconductors to 65 Tesla - Read the full-length publication, Exciton diamagnetic shifts and valley Zeeman effects in monolayer WS2 and MoS2 to 65 tesla, in Nature Communications.
Funding
This research was funded by the following grants: G.S. Boebinger, A.V. Stier, S. A. Crooker (NSF DMR-1157490); B.T. Jonker (NRL Nanoscience Institute; AFOSR AOARD 14IOA018-134141); J. Kono (AFOSR FA9550-14-1-0268)
For more information, contact Chuck Mielke.