Impact of connectivity on the electronic structure of N-heterotriangulenes
N-heterotriangulenes (N-HTAs) are promising organic semiconductors for applications in field effect transistors and solar cells. Thereby the electronic structure of organic/metal interfaces and thin films is essential for the performance of organic-molecule-based devices. Here, we studied the struct...
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| Main Authors: | , , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
January 12, 2023
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| In: |
The journal of physical chemistry. C, Energy, materials, and catalysis
Year: 2023, Volume: 127, Issue: 1, Pages: 542-549 |
| ISSN: | 1932-7455 |
| DOI: | 10.1021/acs.jpcc.2c05737 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1021/acs.jpcc.2c05737
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| Author Notes: | Mohsen Ajdari, Ronja Pappenberger, Christian Walla, Marvin Hoffmann, Ina Michalsky, Milan Kivala, Andreas Dreuw, and Petra Tegeder |
| Summary: | N-heterotriangulenes (N-HTAs) are promising organic semiconductors for applications in field effect transistors and solar cells. Thereby the electronic structure of organic/metal interfaces and thin films is essential for the performance of organic-molecule-based devices. Here, we studied the structural and the electronic properties of two different N-HTAs, N-HTA 550 and N-HTA 557, the latter containing an additional 7-membered ring, adsorbed on Au(111) using vibrational and electronic high-resolution electron energy loss spectroscopy in combination with state-of-the-art quantum chemical calculations. In the mono- and multilayer, both N-HTAs adopt a planar adsorption geometry with the molecular backbone oriented parallel to the gold substrate. The energies of the lowest excited electronic singlet states (S) are assigned. The optical gap (S0 → S1 transition) is found to be 3.4 eV for N-HTA 550 and 2.5 eV for N-HTA 557. Thus, the introduction of the −C═C- double bond in N-HTA 557 resulted in a pronounced decrease of the optical gap size by 0.9 eV due to the larger π-conjugated electron system compared to N-HTA 550. Structural variations or substitution patterns in N-HTAs foster the opportunity for tailoring their electronic properties. |
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| Physical Description: | Online Resource |
| ISSN: | 1932-7455 |
| DOI: | 10.1021/acs.jpcc.2c05737 |