Interlayer exciton dynamics in a dichalcogenide monolayer heterostructure. (9th June 2017)

• Record Type: Journal Article
• Authors: Nagler, Philipp; Plechinger, Gerd; Ballottin, Mariana V; Mitioglu, Anatolie; Meier, Sebastian; Paradiso, Nicola; Strunk, Christoph; Chernikov, Alexey; Christianen, Peter C M; Schüller, Christian; Korn, Tobias
• Is Part Of: 2D materials. Volume 4:Number 2(2017)
• Publication Date: 2017-06-09
• Subjects: transition-metal dichalcogenides -- heterostructures -- interlayer excitons; Graphene -- Periodicals; Materials science -- Periodicals; Nanostructured materials -- Periodicals; 620.115
• DOI: 10.1088/2053-1583/aa7352
• Languages: English
• ISSNs: 2053-1583

Abstract

Abstract: In heterostructures consisting of different transition-metal dichalcogenide monolayers, a staggered band alignment can occur, leading to rapid charge separation of optically generated electron–hole pairs into opposite monolayers. These spatially separated electron–hole pairs are Coulomb-coupled and form interlayer excitons. Here, we study these interlayer excitons in a heterostructure consisting of MoSe2 and WSe2 monolayers using photoluminescence spectroscopy. We observe a non-trivial temperature dependence of the linewidth and the peak energy of the interlayer exciton, including an unusually strong initial redshift of the transition with temperature, as well as a pronounced blueshift of the emission energy with increasing excitation power. By combining these observations with time-resolved photoluminescence measurements, we are able to explain the observed behavior as a combination of interlayer exciton diffusion and dipolar, repulsive exciton-exciton interaction.