Polarization and time-resolved photoluminescence spectroscopy of excitons in MoSe 2 monolayers

Gang Wang (1) , Etienne Palleau (1) , Thierry Amand (1) , S. Tongay (2) , Xavier Marie (1) , B. Urbaszek (1)

1 LPCNO - Laboratoire de physique et chimie des nano-objets
2 ASU - School for Engineering of Matter, Transport and Energy

We investigate valley exciton dynamics in MoSe2 monolayers in polarization- and time-resolved photoluminescence (PL) spectroscopy at 4 K. Following circularly polarized laser excitation, we record a low circular polarization degree of the PL of typically ≤5%. This is about 10 times lower than the polarization induced under comparable conditions in MoS2 and WSe2 monolayers. The evolution of the exciton polarization as a function of excitation laser energy and power is monitored in PL excitation experiments. Fast PL emission times are recorded for both the neutral exciton of ≤3 ps and for the charged exciton (trion) of 12 ps.

Domaines: Chimie

Gang Wang, Etienne Palleau, Thierry Amand, S. Tongay, Xavier Marie, et al.. Polarization and time-resolved photoluminescence spectroscopy of excitons in MoSe 2 monolayers. Applied Physics Letters, 2015, 106 (11), pp.112101. ⟨hal-02049146⟩