Evidence for line width and carrier screening effects on excitonic valley relaxation in 2D semiconductors.

ABSTRACT: Monolayers of transition metal dichalcogenides (TMDC) have recently emerged as excellent platforms for exploiting new physics and applications relying on electronic valley degrees of freedom in two-dimensional (2D) systems. Here, we demonstrate that Coulomb screening by 2D carriers plays a critical role in excitonic valley pseudospin relaxation processes in naturally carrier-doped WSe₂ monolayers (1L-WSe₂). The exciton valley relaxation times were examined using polarization- and time-resolved photoluminescence spectroscopy at temperatures ranging from 10 to 160 K. We show that the temperature-dependent exciton valley relaxation times in 1L-WSe₂ under various exciton and carrier densities can be understood using a unified framework of intervalley exciton sc

SUBMITTER: Miyauchi Y 

PROVIDER: S-EPMC6030139 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature