Unraveling the Effect of Stacking Configurations on Charge Transfer in WS 2 and Organic Semiconductor Heterojunctions
[1];
[4];
[2]
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, Indiana 47907, United States, Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907, United States
Photoinduced interfacial charge transfer plays a critical role in energy conversion involving van der Waals (vdW) heterostructures constructed of inorganic nanostructures and organic materials. However, the effect of molecular stacking configurations on charge transfer dynamics is less understood. In this study, we demonstrated the tunability of interfacial charge separation in a type-II heterojunction between monolayer (ML) WS2 and an organic semiconducting molecule [2-(3"',4'-dimethyl-[2,2':5',2':5",2"'-quaterthiophen]-5-yl)ethan-1-ammonium halide (4Tm)] by rational design of relative stacking configurations. The assembly between ML-WS2 and the 4Tm molecule forms a face-to-face stacking when 4Tm molecules are in a self-aggregation state. In contrast, a face-to-edge stacking is observed when 4Tm molecule is incorporated into a 2D organic–inorganic hybrid perovskite lattice. The face-to-face stacking was proved to be more favorable for hole transfer from WS2 to 4Tm and led to interlayer excitons (IEs) emission. Transient absorption measurements show that the hole transfer occurs on a time scale of 150 fs. On the other hand, the face-to-edge stacking resulted in much slower hole transfer without formation of IEs. This inefficient hole transfer occurs on a similar time scale as A exciton recombination in WS2, leading to the formation of negative trions. These investigations offer important fundamental insights into the charge transfer processes at organic–inorganic interfaces.
- Research Organization:
- Purdue Univ., West Lafayette, IN (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- SC0022082
- OSTI ID:
- 1986581
- Alternate ID(s):
- OSTI ID: 2004661
- Journal Information:
- Precision Chemistry, Journal Name: Precision Chemistry Vol. 1 Journal Issue: 7; ISSN 2771-9316
- Publisher:
- American Chemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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