Exciton dynamics in WSe2 bilayers

Abstract

We investigate exciton dynamics in 2H-WSe2 bilayers in time-resolved photoluminescence (PL) spectroscopy. Fast PL emission times are recorded for both the direct exciton with ${\tau }_D$ ~ 3 ps and the indirect optical transition with ${\tau }_i$ ~ 25 ps. For temperatures between 4 to 150 K ${\tau }_i$ remains constant. Following polarized laser excitation, we observe for the direct exciton transition at the K point of the Brillouin zone efficient optical orientation and alignment during the short emission time ${\tau }_D$. The evolution of the direct exciton polarization and intensity as a function of excitation laser energy is monitored in PL excitation (PLE) experiments.

4 pages, 3 figures

References in corpus (10)

• The Valley Hall Effect in MoS2 Transistors
• Observation of giant bandgap renormalization and excitonic effects in a monolayer transition metal dichalcogenide semiconductor
• Tightly bound excitons in monolayer WSe2
• Probing Excitonic Dark States in Single-layer Tungsten Disulfide
• High-temperature superfluidity with indirect excitons in van der Waals heterostructures
• Anomalous Raman Spectra and Thickness Dependent Electronic properties of WSe2
• Robust optical emission polarization in MoS2 monolayers through selective valley excitation
• Nuclear spin physics in quantum dots: an optical investigation
• Exciton Valley Dynamics probed by Kerr Rotation in WSe2 Monolayers
• Theory optical excitation spectra and depolarization dynamics in bilayer WS${}_2$ from viewpoint of excimers