title: Tightly Bound Trions in Transition Metal Dichalcogenide Heterostructures.
abstract: We report the observation of trions at room temperature in a van der Waals heterostructure composed of MoSe2 and WS2 monolayers. These trions are formed by excitons excited in the WS2 layer and electrons transferred from the MoSe2 layer. Recombination of trions results in a peak in the photoluminescence spectra, which is absent in monolayer WS2 that is not in contact with MoSe2. The trion origin of this peak is further confirmed by the linear dependence of the peak position on excitation intensity. We deduced a zero-density trion binding energy of 62 meV. The trion formation facilitates electrical control of exciton transport in transition metal dichalcogenide heterostructures, which can be utilized in various optoelectronic applications.
authors.affiliation: Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045, United States.
authors.forename: Matthew Z
authors.initials: MZ
authors.lastname: Bellus
authors.affiliation: Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045, United States.
authors.forename: Frank
authors.initials: F
authors.lastname: Ceballos
authors.affiliation: Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045, United States.
authors.forename: Hsin-Ying
authors.initials: HY
authors.lastname: Chiu
authors.affiliation: Department of Physics and Astronomy, The University of Kansas, Lawrence, Kansas 66045, United States.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhao
keywords: charge transfer; exciton; photoluminescence; transition metal dichalcogenides; trion; van der Waals heterostructure