Probing charge transfer excitons in a MoSe2–WS2 van der Waals heterostructure. Issue 41 (7th October 2015)

• Record Type: Journal Article
• Authors: Ceballos, Frank; Bellus, Matthew Z.; Chiu, Hsin-Ying; Zhao, Hui
• Is Part Of: Nanoscale. Volume 7:Issue 41(2015)
• Page Start: 17523
• Page End: 17528
• Publication Date: 2015-10-07
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c5nr04723d
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Charge transfer excitons are observed in a van der Waals heterostructures formed by monolayer transition metal dichalcogenides. Abstract : We show that the van der Waals heterostructure formed by MoSe2 and WS2 provides a unique system with near degenerate interlayer and intralayer excitonic states. Photoluminescence measurements indicate that the charge transfer exciton states are approximately 50 meV below the MoSe2 exciton states, with a significant spectral overlap. The transient absorption of a femtosecond pulse was used to study the dynamics of the charge transfer excitons at room temperature. We found a lifetime of approximately 80 ps for the charge transfer excitons. A diffusion coefficient of about 14 cm 2 s −1 was deduced, which is comparable to individual excitons in transition metal dichalcogenides.