Charge transfer dynamics and interlayer exciton formation in MoS2/VOPc mixed dimensional heterojunction

Madison C. Schwinn, Shahnawaz Rafiq, Changmin Lee, Matthew P. Bland, Thomas W. Song, Vinod K. Sangwan, Mark C. Hersam, Lin X. Chen

Research output: Contribution to journalArticlepeer-review

7 Scopus citations

Abstract

Mixed-dimensional van der Waals heterojunctions involve interfacing materials with different dimensionalities, such as a 2D transition metal dichalcogenide and a 0D organic semiconductor. These heterojunctions have shown unique interfacial properties not found in either individual component. Here, we use femtosecond transient absorption to reveal photoinduced charge transfer and interlayer exciton formation in a mixed-dimensional type-II heterojunction between monolayer MoS2 and vanadyl phthalocyanine (VOPc). Selective excitation of the MoS2 exciton leads to hole transfer from the MoS2 valence band to VOPc highest occupied molecular orbit in ∼710 fs. On the contrary, selective photoexcitation of the VOPc layer leads to instantaneous electron transfer from its excited state to the conduction band of MoS2 in less than 100 fs. This light-initiated ultrafast separation of electrons and holes across the heterojunction interface leads to the formation of an interlayer exciton. These interlayer excitons formed across the interface lead to longer-lived charge-separated states of up to 2.5 ns, longer than in each individual layer of this heterojunction. Thus, the longer charge-separated state along with ultrafast charge transfer times provide promising results for photovoltaic and optoelectronic device applications.

Original languageEnglish
Article number184701
JournalJournal of Chemical Physics
Volume157
Issue number18
DOIs
StatePublished - Nov 14 2022

Bibliographical note

Publisher Copyright:
© 2022 Author(s).

ASJC Scopus subject areas

  • General Physics and Astronomy
  • Physical and Theoretical Chemistry

Fingerprint

Dive into the research topics of 'Charge transfer dynamics and interlayer exciton formation in MoS2/VOPc mixed dimensional heterojunction'. Together they form a unique fingerprint.

Cite this