Electrically Controlled Interfacial Charge Transfer Induced Excitons in MoSe2-WSe2 Lateral Heterostructure

arXiv (Cornell University)

Abstract

Controlling excitons and their transport in two-dimensional (2D) transition metal dichalcogenides (TMDs) heterostructures is central to advancing photonics and electronics on-chip integration. We investigate the controlled generation and manipulation of excitons and their complexes in monolayer (1L) MoSe2-WSe2 lateral heterostructure (LHS), directly grown via water-assisted chemical vapor deposition. Using a field-effect transistor design by incorporating a few-layer graphene back gate, single-layer graphene edge contact and encapsulation with few-layer hexagonal boron nitride, we achieve precise electrical tuning of exciton complexes and their transfer across 1D interfaces. At cryogenic temperatures (4 K), photoluminescence and photocurrent maps reveal the synergistic effect of local electric field and interface phenomena in the modulation of excitons, trions, and free carriers. We observe spatial variations in exciton and trion densities driven by exciton-trion conversion under electrical manipulation. The first-principle density functional theory calculation reveals significant band modification at the lateral interfaces and graphene-TMDs contact region. Furthermore, we demonstrate the versatility of 2D TMDS LHS in hosting and manipulating quantum emitters, achieving precise control over narrow-band emissions through modulating carrier injection and electrical biasing. This work extends the boundary of the present understanding of excitonic behaviour within lateral heterojunctions, highlighting the potential for controlled exciton manipulation across 1D interfaces and paving the way for next-generation electro-optical quantum devices.

Authors 11

1. Baisali Kundu

   Indian Institute of Technology Kharagpur

   Affiliation as printed

   Materials Science Centre, Indian Institute of Technology, Kharagpur 721302, India

2. David Tebbe Aachen 2nd Institute of Physics and JARA-FIT

   RWTH Aachen University

   Affiliation as printed

   2nd Institute of Physics and JARA-FIT, RWTH Aachen University, Aachen 52056, Germany

3. Md. Nur Hassan

   Uppsala University

   Affiliation as printed

   Department of Physics and Astronomy, Uppsala University, Uppsala 75120, Sweden

4. Suman Kumar Chakraborty

   Indian Institute of Technology Kharagpur

   Affiliation as printed

   Materials Science Centre, Indian Institute of Technology, Kharagpur 721302, India

5. Marvin Metzelaars Aachen Institute of Inorganic Chemistry

   RWTH Aachen University

   Affiliation as printed

   Institute of Inorganic Chemistry, RWTH Aachen University, 52074 Aachen, Germany

6. Paul Kögerler Aachen Institute of Inorganic Chemistry

   RWTH Aachen University

   Affiliation as printed

   Institute of Inorganic Chemistry, RWTH Aachen University, 52074 Aachen, Germany

7. Debjani Karmakar

   Uppsala University · Bhabha Atomic Research Centre · Homi Bhabha National Institute

   Affiliation as printed

   Department of Physics and Astronomy, Uppsala University, Uppsala 75120, Sweden

   Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India

   Homi Bhabha National Institute, Trombay, Mumbai 400094, India

8. Christoph Stampfer Aachen 2nd Institute of Physics and JARA-FIT

   RWTH Aachen University

   Affiliation as printed

   2nd Institute of Physics and JARA-FIT, RWTH Aachen University, Aachen 52056, Germany

9. Bernd Beschoten Aachen 2nd Institute of Physics and JARA-FIT

   RWTH Aachen University

   Affiliation as printed

   2nd Institute of Physics and JARA-FIT, RWTH Aachen University, Aachen 52056, Germany

10. Lutz Waldecker Aachen 2nd Institute of Physics and JARA-FIT

    RWTH Aachen University

    Affiliation as printed

    2nd Institute of Physics and JARA-FIT, RWTH Aachen University, Aachen 52056, Germany

11. Prasana Kumar Sahoo

    Indian Institute of Technology Kharagpur

    Affiliation as printed

    Materials Science Centre, Indian Institute of Technology, Kharagpur 721302, India