Ryu, Huije Kwon, Junyoung Yang, Seunghoon Watanabe, Kenji Taniguchi, Takashi Kim, Young Duck Hone, James Lee, Chul-Ho Lee, Gwan-Hyoung 2024-01-19T13:03:03Z 2024-01-19T13:03:03Z 2022-04-03 2021-12-15 2330-4022 https://pubs.kist.re.kr/handle/201004/115933 Transition metal dichalcogenides (TMDs) and their van der Waals heterostructures provide a unique platform for optoelectronic applications. The strong Coulomb interaction in TMDs creates various tightly bound electron-hole combinations, resulting in various exciton complexes. Despite the great potential of exciton complexes in optoelectronics, most related studies have been performed using optical excitation methods at low temperatures. Here, we demonstrate the electrical modulation of exciton complexes in light-emitting tunnel transistors (LETTs) of van der Waals heterostructures with tunnel junctions of monolayer WSe2 sandwiched by tunnel barriers of hexagonal boron nitride (hBN) and graphene electrodes. Electrons and holes were electrically driven into the monolayer WSe2 by tunneling through hBN, leading to strong electroluminescence (EL) via recombination. To electrically control the exciton complexes by varying the charge balance, we constructed an additional electrode (control electrode) in direct contact with WSe2. We substantially modulated the Fermi energy of WSe2 by direct injection or extraction of electrons from the control electrode, allowing for the modulation of exciton complexes such as excitons, trions, and exciton-polarons, in strong room-temperature EL. This work provides a novel way to electrically stabilize exciton complexes in light-emitting devices of van der Waals heterostructures, which is beneficial for electrically driven excitonic devices. English AMER CHEMICAL SOC DIODES Electrical Modulation of Exciton Complexes in Light-Emitting Tunnel Transistors of a van der Waals Heterostructure Article 10.1021/acsphotonics.1c01286 1 ACS PHOTONICS, v.8, no.12, pp.3455 - 3461 ACS PHOTONICS 8 12 3455 3461 scie scopus 000753681400006 2-s2.0-85119070879 Nanoscience & Nanotechnology Materials Science, Multidisciplinary Optics Physics, Applied Physics, Condensed Matter Science & Technology - Other Topics Materials Science Optics Physics Article DIODES two-dimensional materials van der Waals heterostructures WSe2 light-emitting device electroluminescence exciton complexes trion room temperature