Confined excitons in CdSe/CdMnS and CdSe/ZnMnS nanoplatelets

ORAL

Abstract

We have used absorption and PL spectroscopies to study the magneto-optical properties of colloidal CdSe/CdMnS and CdSe/ZnMnS core-shell nanoplatelets. We observe three absorption features tentatively attributed to the e1h1, e1l1, and e2h2 confined excitons. In the presence of a magnetic field B applied normal to the substrate surface, the PL from e1h1 becomes circularly polarized as σ+, indicating the presence of exchange interaction between the carrier spins and the spins of the Mn2+ ions. The circular polarization initially increases with B and saturates at 4T. At a fixed B the circular polarization decreases with increasing temperature and vanishes around 50K. The circular polarization peak, unlike previously studied samples [1], coincides with the e1h1 exciton. This is attributed to the smaller thickness (2ML) of the CdSe core compared to the previously studied samples (5ML).
We also measured the e1h1 exciton magnetic splitting from the magneto-transmission spectra. Saturation splittings up to 5 meV have been observed.
1- J.R. Murphy et. al., Applied Physics Letters 108,242406 (2016).

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Presenters

  • Arman Najafi

    Department of Physics, University at Buffalo SUNY, Buffalo, NY, University at Buffalo, The State University of New York, Physics, State Univ of NY - Buffalo, Physics, University at Buffalo, State University of New York

Authors

  • Arman Najafi

    Department of Physics, University at Buffalo SUNY, Buffalo, NY, University at Buffalo, The State University of New York, Physics, State Univ of NY - Buffalo, Physics, University at Buffalo, State University of New York

  • Peiyao Zhang

    Department of Physics, University at Buffalo SUNY, Buffalo, NY, University at Buffalo, The State University of New York, Physics, State Univ of NY - Buffalo, Physics, University at Buffalo, State University of New York

  • Tenzin Norden

    Department of Physics, University at Buffalo SUNY, Buffalo, NY, University at Buffalo, The State University of New York, Physics, State Univ of NY - Buffalo, Physics, University at Buffalo, State University of New York

  • Arinjoy Bhattacharya

    Department of Physics, University at Buffalo SUNY, Buffalo, NY, University at Buffalo, The State University of New York

  • James Pientka

    Physics, ST. BONAVENTURE UNIVERSITY, Department of Physics, St. Bonaventure University, St. Bonaventure, NY, St. Bonaventure University

  • Sushant Shendre

    LUMINOUS! Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore

  • Savas Delikanli

    LUMINOUS! Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore

  • Hilmi Volkan Demir

    LUMINOUS! Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore

  • Athos Petrou

    Department of Physics, University at Buffalo SUNY, Buffalo, NY, University at Buffalo, The State University of New York, Physics, State Univ of NY - Buffalo, Physics, University at Buffalo, State University of New York