Observation of Polaronic Trions in MoS<sub>2</sub>/SrTiO<sub>3</sub> Heterostructures

ORAL

Abstract


One of the primary challenges in condensed matter physics has been to understand the dynamics of many body interactions of quasiparticles. Recently, the three body charged quasiparticle, trion, has attracted a lot of attention, due to its large binding energies in 2D transition metal dichalcogenide (TMD) semiconductors, and their have been several efforts to tune its properties. The tunability of trion using phonon interactions has not yet been achieved due to the lack of low frequency phonons in 2D systems. In this work, for the first time, we demonstrate trion-phonon interactions across the interface of a MoS2/SrTiO3 heterostructure. From PL emission experiments, we observe that the low frequency (soft) phonon mode in SrTiO3, due to its polar nature, selectively couples with the charged trions in MoS2 to form a quasi-stationary bound state, which we call the ‘Polaronic Trion’. We demonstrate tunability of the light emission from the Polaronic Trion by almost 90 meV by varying electric field, temperature or even crystal orientation. Such an unprecedented selective tunability of the trion would probably guide practical applications for the much investigated quasiparticles in 2D materials.

*NRF Singapore, SinBerise

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Presenters

  • Soumya Sarkar

    • NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore

Authors

  • Soumya Sarkar

    • NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore

  • Sinu Mathew

    • Nanoscience and Nanotechnology Institute, National University of Singapore

  • Maxim Trushin

    • Centre for Advanced 2D Materials, National University of Singapore

  • Sreetosh Goswami

    • NUSNNI, National University of Singapore
    • NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore

  • surajit saha

    • Nanoscience and Nanotechnology Institute, National University of Singapore

  • Majid Fard

    • Nanoscience and Nanotechnology Institute, National University of Singapore

  • Saurav Prakash

    • NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore

  • Sherman Tan

    • NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore

  • Antony George

    • Rice University

  • kian ping loh

    • Centre for Advanced 2D Materials, National University of Singapore

  • Pulickel Ajayan

    • Materials Science & NanoEngineering, Rice University
    • MSNE, Rice Univ
    • Department of Materials Science and Nano Engineering, Rice University
    • Department of Materials Science and Nanoengineering, Rice university
    • Rice University

  • Shaffique Adam

    • Centre for Advanced 2D Materials, National University of Singapore
    • Yale-NUS College
    • Department of Physics and Centre for Advanced 2D Materials, National University of Singapore
    • Yale-NUS College and Natl Univ of Singapore

  • Thirumalai Venkatesan

    • Department of Physics & NUSNNI-NanoCore, Natl Univ of Singapore
    • Department of Physics, National University of Singapore
    • NUSNNI, National University of Singapore
    • Natl Univ of Singapore
    • Nanoscience and Nanotechnology Institute, National University of Singapore
    • National University of Singapore