Tunable PL in W-based TMDs probed by optical vortex beam

ORAL

Abstract

Selection rules for optical transitions in monolayer transition metal dichalcogenides are governed by the spin and valley degree of freedom of excitons. The intravalley scattering dynamics is responsible for photoluminescence (PL) quenching in WS2 and WSe2 at low temperature. The PL intensity of bright exciton at steady state is determined by intravalley scattering rate between bright and dark exciton states. In this work we propose a technique to probe the PL spectrum of monolayer W-based TMDs via photo excitation utilizing optical vortex beam and investigate the effect of intravalley scattering.

*S. D. acknowledges Science and Engineering Research Board (SB/S2/RJN-110/2016) Ramanujan Fellowship, Ministry of Education STARS (MoE/STARS-1/647), Indian Institute of Technology Kharagpur (IIT/SRIC/ISIRD/2017-2018), and Ministry of Human Resource Development (IIT/SRIC/PHY/NTS/2017-18/75) for the funding and support for this work. D. C. acknowledges Council of Scientific and Industrial Research, JRF (09/081(1352)/2019-EMR-I) for the financial assistance.

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Presenters

  • Aswini K Pattanayak

    • Indian Institute of Technology Kharagpur
    • Indian Institute of Technology, Kharagpur

Authors

  • Aswini K Pattanayak

    • Indian Institute of Technology Kharagpur
    • Indian Institute of Technology, Kharagpur

  • Pritam Das

    • Indian Institute of Technology, Kharagpur

  • Devarshi Chakrabarty

    • Indian Institute of Technology Kharagpur
    • Indian Institute of Technology, Kharagpur

  • Avijit Dhara

    • Indian Institute of Technology Kharagpur
    • Indian Institute of Technology, Kharagpur

  • Shreya Paul

    • Indian Institute of Technology, Kharagpur

  • Maruthi M Brundavanam

    • Indian Institute of Technology, Kharagpur

  • Sajal Dhara

    • Indian Institute of Technology Kharagpur
    • Indian Institute of Technology, Kharagpur