Photoluminescence Saturation and Exciton Decay Dynamics in Transition Metal Dichalcogenide Monolayers

Abstract

We report a photoluminescence (PL) and transient reflection spectroscopy study of exciton dynamics in monolayer transition transition-metal dichalcogenides (TMDs). PL saturation in monolayer MoSe2 occurs an excitation intensity more than two orders of magnitude lower than in monolayer MoS2. Transient reflection shows that the nonlinear exciton-exciton annihilation is the dominant exciton decay process in monolayer MoSe2 in contrast to the previously reported linear exciton decay in monolayer MoS2. In addition, the exciton lifetime in MoSe2, > 125 ps, is more than an order of magnitude longer than the several-ps exciton lifetime in MoS2. We find that the dramatically different exciton decay mechanism and PL saturation behavior of MoSe2 and MoS2 monolayers can be explained by the difference in their exciton lifetime.

This manuscript is withdrawn due to incomplete introduction and reference

References in corpus (4)

• Two Dimensional Atomic Crystals
• Valley polarization in MoS2 monolayers by optical pumping
• Valley Dependent Optoelectronics from Inversion Symmetry Breaking
• Exciton Valley Dynamics probed by Kerr Rotation in WSe2 Monolayers

Cited by in corpus (4)

• Exciton formation assisted by longitudinal optical phonons in monolayer transition metal dichalcogenides
• Electron-phonon interaction, excitations and ultrafast photoemission from doped monolayer MoS2
• Nonexponential photoluminescence dynamics in an inhomogeneous ensemble of excitons in WSe${}_2$ monolayers
• Selectively strong coupling MoS${}_2$ excitons to a metamaterial at room temperature