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Abstract The electronic properties of 2D materials play a critical role in determining their potential for device applications. Despite rapid developments in 2D semiconductors, studies of fundamental electronic parameters, including the electronic gap and ionization energy, are limited, with significant discrepancies in reported values. The study focuses on tungsten disulfide (WS₂) and investigates the electronic structure of films comprising an increasing number of layers deposited with two different methods: direct synthesis via metal–organic chemical vapor deposition (MOCVD) and additive mechanical transfer of exfoliated single layers. The films are characterized via Raman, UV–vis, and photoluminescence spectroscopies, as well as ultraviolet photoelectron and inverse photoemission spectroscopies (UPS/IPES). The electronic gap of WS₂ is found to decrease from 2.43 eV for the monolayer to 1.97 eV for the trilayer, indicating a bulk transition at the trilayer thickness. This reduction in the electronic gap is primarily due to the downward shift of the conduction band minimum relative to the valence band maximum. A comparative analysis with MOCVD‐grown WS₂ reveals a slightly larger electronic gap for MOCVD‐grown samples, attributed to differences in defect densities. The electronic levels evaluated through UPS/IPES highlight the significant influence of preparation methods on the electronic properties of WS₂.
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Synthesis and study of fluorine-functionalized ZnTPPs
Five ZnTPP derivatives, fluorinated either on the meso phenyl rings or in β-positions and reference compounds were synthesized and their electronic structure was studied experimentally and computationally to determine the steric and electronic effects of fluorine substitution.
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- PAR ID:
- 10381888
- Date Published:
- Journal Name:
- Journal of Porphyrins and Phthalocyanines
- Volume:
- 26
- Issue:
- 04
- ISSN:
- 1088-4246
- Page Range / eLocation ID:
- 295 to 307
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1142/S1088424622500146
