High room temperature optical polarization due to spin-valley coupling in monolayer WS2
Abstract
We prepare single-layer WS2 films such that the photoluminescence is from either the neutral exciton or the negatively charged trion. While the neutral exciton emission has zero polarization at room temperature, we observe a room temperature optical polarization in excess of 40% for the trion. Using an applied gate voltage, we can modulate the electron density, and subsequently the polarization of the trion emission continuously from 20-40%. Both the polarization and the emission energy monotonically track the gate voltage with the emission energy increasing by 45 meV. We discuss the role electron capture by the exciton has on suppressing the intervalley scattering process.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 22, 2016
- Source ID
- 10.1063/1.4942797
Entities
People
- A. L. Friedman
- A. T. Hanbicki
- Berend T Jonker
- C. S. Hellberg
- G. Kioseoglou
- K. M. Mccreary
- M. Currie
Organizations
- Air Force Office of Scientific Research
- United States Naval Research Laboratory
- University of Crete