Valley-polarized exciton dynamics in a 2D semiconductor heterostructure

Pasqual Rivera, Kyle L. Seyler, Hongyi Yu, John R. Schaibley, Jiaqiang Yan, David G. Mandrus, Wang Yao, Xiaodong Xu

Research output: Contribution to journalArticlepeer-review

452 Scopus citations

Abstract

Heterostructures comprising different monolayer semiconductors provide an attractive setting for fundamental science and device technologies, such as in the emerging field of valleytronics. We realized valley-specific interlayer excitons in monolayer WSe2-MoSe2 vertical heterostructures. We created interlayer exciton spin-valley polarization by means of circularly polarized optical pumping and determined a valley lifetime of 40 nanoseconds. This long-lived polarization enables the visualization of the expansion of a valley-polarized exciton cloud over several micrometers. The spatial pattern of the polarization evolves into a ring with increasing exciton density, a manifestation of valley exciton exchange interactions. Our work introduces van der Waals heterostructures as a promising platform from which to study valley exciton physics.

Original languageEnglish (US)
Pages (from-to)688-691
Number of pages4
JournalScience
Volume351
Issue number6274
DOIs
StatePublished - Feb 12 2016
Externally publishedYes

ASJC Scopus subject areas

  • General

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