Reversible Electrical Control of Interfacial Charge Flow across van der Waals Interfaces
Fu, Shuai (Max Planck Institute for Polymer Research (Germany))
Jia, Xiaoyu (Max Planck Institute for Polymer Research (Germany))
Hassan, Aliaa S. (Max Planck Institute for Polymer Research (Germany))
Zhang, Heng (Max Planck Institute for Polymer Research (Germany))
Zheng, Wenhao (Max Planck Institute for Polymer Research (Germany))
Gao, Lei (Max Planck Institute for Polymer Research (Germany))
Di Virgilio, Lucia (Max Planck Institute for Polymer Research (Germany))
Krasel, Sven (Max Planck Institute for Polymer Research (Germany))
Beljonne, David (Université de Mons)
Tielrooij, Klaas-Jan (Institut Català de Nanociència i Nanotecnologia)
Bonn, Mischa (Max Planck Institute for Polymer Research (Germany))
Wang, Hai I. (Max Planck Institute for Polymer Research (Germany))

Date:	2023
Abstract:	Bond-free integration of two-dimensional (2D) materials yields van der Waals (vdW) heterostructures with exotic optical and electronic properties. Manipulating the splitting and recombination of photogenerated electron-hole pairs across the vdW interface is essential for optoelectronic applications. Previous studies have unveiled the critical role of defects in trapping photogenerated charge carriers to modulate the photoconductive gain for photodetection. However, the nature and role of defects in tuning interfacial charge carrier dynamics have remained elusive. Here, we investigate the nonequilibrium charge dynamics at the graphene-WS vdW interface under electrochemical gating by operando optical-pump terahertz-probe spectroscopy. We report full control over charge separation states and thus photogating field direction by electrically tuning the defect occupancy. Our results show that electron occupancy of the two in-gap states, presumably originating from sulfur vacancies, can account for the observed rich interfacial charge transfer dynamics and electrically tunable photogating fields, providing microscopic insights for optimizing optoelectronic devices.
Grants:	European Commission 804349
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Van der Waals heterostructures ; Charge transfer ; Photogating ; Electrochemical gating ; Operando terahertz spectroscopy
Published in:	Nano letters, Vol. 23, Issue 5 (March 2023) , p. 1850-1857, ISSN 1530-6992

DOI: 10.1021/acs.nanolett.2c04795
PMID: 36799492

8 p, 3.2 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles