Work

Nature of Long-Lived Moiré Interlayer Excitons in Electrically Tunable MoS2/MoSe2 Heterobilayers.

Year: 2024

Type: article

Abstract: Interlayer excitons in transition-metal dichalcogenide heterobilayers combine high binding energy and valley-contrasting physics with a long optical lifetime and strong dipolar character. Their permanent electric dipole enables electric-field control of the emission energy, lifetime, and location. Device material and geometry impact the nature of the interlayer excitons via their real- and momentum-space configurations. Here, we show that interlayer excitons in MoS2/MoSe2 heterobilayers are formed by charge carriers residing at the Brillouin zone edges, with negligible interlayer hybridization. We find that the moiré superlattice leads to the reversal of the valley-dependent optical selection rules, yielding a positively valued g-factor and cross-polarized photoluminescence. Time-resolved photoluminescence measurements reveal that the interlayer exciton population retains the optically induced valley polarization throughout its microsecond-long lifetime. The combination of a long optical lifetime and valley polarization retention makes MoS2/MoSe2 heterobilayers a promising platform for studying fundamental bosonic interactions and developing excitonic circuits for optical information processing.

Source: Apollo (University of Cambridge)

DOI: 10.17863/cam.111780

Authors: Alexeev, Evgeny M, Purser, Carola M, Gilardoni, Carmem M, Kerfoot, James, Chen, Hao, Cadore, Alisson R, Rosa, Bárbara LT, Feuer, Matthew SG, Javary, Evans, Hays, Patrick, Watanabe, Kenji, Taniguchi, Takashi, Tongay, Seth Ariel, Kara, Dhiren M, Atatüre, Mete, Ferrari, Andrea C

Language: English

Topic: 2D Materials and Applications

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funders: U.S. Department of Energy, Ministry of Education, Culture, Sports, Science and Technology, Nederlandse Organisatie voor Wetenschappelijk Onderzoek, Engineering and Physical Sciences Research Council, Japan Society for the Promotion of Science

Awards: G157652788, G2130091398, G2442584775, Layered Materials Research Foundry, G2544518203, G2802559971, Engineering van der Waals heterostructures: from atomic level layer-by-layer assembly to printable innovative devices, G2960223313, Graphene Flexible Electronics and Optoelectronics, G4162329948, G4806815962, Metal Atoms on Surfaces & Interfaces (MASI) for Sustainable Future, EPSRC Centre for Doctoral Training in Graphene Technology, G516966722, Graphene Flexible Electronics and Optoelectronics: Bridging The Gap Between Academia and Industry, THE SYNTHESIS 2D JANUS VDW CRYSTALS AND NOVEL QUANTUM PHENOMENA ARISING FROM MIRROR-SYMMETRY BREAKING, G8430280503, Quantum materials by design: Towards engineering spin-based functionality at the atomic level., G898758523

OpenAlex ID: W6906857061

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