Electric Field Dependent Photoluminescence in Atomically Thin Transition Metal Dichalcogenides van der Waals Heterostructures.

ORAL

Abstract

uregui, Alex A. High, Alan Dibos, Andrew Joe, Elgin Gulpinar, Hongkun Park, Philip Kim Harvard University, Physics Department -abstract- Single layer transition metal dichalcogenides (TMDC) are 2-dimensional (2D) semiconductors characterized by a direct optical bandgap and large exciton binding energies (\textgreater 100 meV). We fabricate CQW heterostructures made of 2D TMDCs with hexagonal Boron nitride (BN) as atomically thin barrier and gate dielectric, with top and bottom gate electrodes. We study the evolution of photoluminescence (PL) spectrum with varying BN barrier thickness, electric field, temperature and polarization. Our measured low-temperature (T $=$ 3K) PL peaks show full width at half maxima on the order of \textasciitilde 3meV. We identify the photoluminescence peaks, corresponding to the charged exciton emission, which red shifts and its brightness increases while the neutral exciton emission becomes darker for increasing electric field.

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Authors

  • Luis A. Jauregui

    Harvard University, Department of Physics

  • Alex High

    Harvard University, Department of Physics, Harvard University, Physics Department

  • Alan Dibos

    Harvard University, Department of Physics, Harvard University, Physics Department

  • Andrew Joe

    Harvard University, Department of Physics, Harvard University, Physics Department

  • Elgin Gulpinar

    Harvard University, Department of Physics, Harvard University, Physics Department

  • Hongkun Park

    Harvard University, Department of Physics, Harvard University, Physics Department

  • Philip Kim

    Harvard University, Department of Physics, Department of Physics, Harvard University, Cambridge, MA 02138, USA, Harvard University, Physics Department, Harvard University